Half Step

A half step, also known as a semitone, is the smallest musical interval used in Western music. It represents the difference in pitch between two adjacent notes, such as from E to F or B to C on a piano. On a keyboard, it’s the distance between any key and the next closest key, whether white or black.

Half steps form the building blocks of scales, melodies, and chords. For example, the chromatic scale consists entirely of half steps, moving in small increments across all twelve notes in an octave. In a major or minor scale, however, half steps appear between specific degrees, giving each scale its unique sound and structure.

In music theory, combining two half steps creates a whole step, another fundamental interval. Understanding half and whole steps is essential for learning how scales, chords, and melodies are built. They help musicians grasp musical movement, tension, and resolution, making them crucial in both composition and performance.

Hard Limiter

A hard limiter is an audio processing tool used to control the maximum volume of a sound signal by capping its peak levels at a set threshold. Unlike a compressor, which gradually reduces the volume of loud parts, a hard limiter “cuts off” or “limits” anything above the threshold level, preventing any peaks from exceeding that limit. This helps avoid distortion and ensures the audio remains within a controlled volume range.

In practice, hard limiting is commonly used in mixing and mastering to increase the loudness of a track without allowing peaks to distort or clip. By setting a strict volume ceiling, hard limiters can make quieter parts louder and the overall track sound fuller, but this effect can also reduce the dynamic range (the difference between the softest and loudest parts of a track). When used excessively, hard limiting can make a track sound flat or overly compressed, as it eliminates natural dynamics.

Hard limiters are particularly useful for broadcasting, streaming, and digital formats where consistent volume is essential. They can ensure that audio levels stay within specific guidelines, improving the listener’s experience and preventing damage to speakers or headphones caused by unexpected volume spikes.

In the right context and with careful use, hard limiters can add polish and loudness to a mix, but overuse can lead to an unnatural, harsh sound. Sound engineers often balance hard limiting with other dynamics processing to preserve as much musicality and depth as possible.

Harmonic Series

The harmonic series is a sequence of overtones, or frequencies, that naturally occur above a fundamental frequency when a musical note is played. Each overtone in the harmonic series is a multiple of the fundamental frequency and contributes to the note’s unique timbre, enriching its sound.

Here’s how it works: when a string or column of air vibrates at its base frequency (known as the fundamental), it also vibrates in halves, thirds, quarters, and so on, producing additional tones above the fundamental. These overtones, or harmonics, follow a mathematical pattern—the first harmonic is twice the frequency of the fundamental, the second is three times, the third is four times, and so forth. Each step up the series gets progressively quieter, which is why we often hear only the fundamental note clearly, even though all harmonics are present.

The harmonic series is essential in music theory and acoustics. It helps explain why different instruments have distinct timbres, even when playing the same note, as each instrument emphasizes certain harmonics based on its shape and material. The series also forms the basis for much of Western harmony, as intervals like octaves, fifths, and thirds align closely with the early harmonics, contributing to why these intervals sound pleasing and “natural” to the ear.

Musicians use the harmonic series to shape tones and tuning systems, while audio engineers may enhance or reduce harmonics to achieve the desired sound quality in a recording or mix. In essence, the harmonic series is foundational to both the science and art of music, influencing everything from instrument design to composition.

Harmonics

Harmonics are a series of higher frequencies, or overtones, that occur naturally when a musical note is played. These overtones are faint, high-pitched sounds layered above the fundamental note (the main pitch you hear), and they give each instrument its unique tone, or timbre. Even if we don’t always consciously notice them, harmonics play a big role in shaping the character of sounds in music.

Instruments produce harmonics through a combination of physical factors, like the shape and material of the instrument, as well as how the note is played. For example, on a guitar, when you lightly touch a string at specific points (like the 5th, 7th, or 12th fret) and pluck it, you’ll hear a “harmonic.” This sound is purer and more bell-like because it isolates one of the overtones while reducing the fundamental pitch.

Harmonics follow a specific pattern based on the fundamental frequency of the note. The first harmonic is the loudest and lowest (the fundamental itself), while each subsequent harmonic is quieter and higher in pitch. For instance, the second harmonic is an octave above the fundamental, the third harmonic is a fifth above that, and so on. This series of harmonics gives rise to complex, rich sounds and is why a violin sounds different from a piano, even when playing the same note.

In audio production, harmonics are essential for shaping sounds. Engineers use tools like equalizers and harmonic enhancers to bring out or modify these overtones, adding warmth, brightness, or fullness to a mix. Understanding harmonics helps musicians and producers create textures, build harmonies, and enhance the emotional impact of their music.

Harmony

Harmony is the combination of different musical notes played or sung simultaneously to produce a pleasing sound. In essence, harmony complements the main melody, adding depth, emotion, and texture to music. When two or more notes are played together, they can create various types of chords (such as major, minor, diminished, and augmented), which evoke different feelings and moods in the listener.

In music theory, harmony is often built on the concept of chord progressions—a sequence of chords that supports the melody and gives a song its structure. These progressions are a fundamental aspect of many genres, from classical to pop, helping to shape the song’s emotional landscape.

Harmony can be consonant or dissonant. Consonant harmony sounds stable, pleasant, and resolved, while dissonant harmony feels tense, creating a sense of instability that often leads back to consonance for resolution. Musicians use these contrasts to create dynamics and emotional flow within a piece.

In vocal music, harmony is commonly achieved through vocal harmonization, where backup singers or additional vocal tracks add complementary notes to the lead melody, creating a fuller sound. Instruments, too, can harmonize, either by playing chords or by layering different pitches that blend well together.

From simple folk songs to complex orchestral compositions, harmony is a vital element that adds richness and complexity to music, enhancing the listener’s experience and conveying emotion in ways that melody alone cannot.

Harmony Vocals

Harmony vocals are additional vocal parts sung at different pitches to complement the main melody. These harmonizing voices create chords and add depth, richness, and texture to a song, enhancing its emotional impact. Harmony vocals can be sung by backup singers or created by layering multiple tracks of the lead vocalist singing in harmony.

In music, harmony vocals typically follow a consistent interval pattern, often singing thirds, fifths, or octaves above or below the main vocal line. The choice of intervals and harmony style depends on the genre and the mood of the song. For instance, pop and rock music often use close, consonant harmonies for a warm and cohesive sound, while folk and country music frequently feature tight, close-knit harmonies that give a natural and organic feel.

Harmony vocals are arranged to match or accentuate key points in the song, like the chorus or bridge, to build intensity and add interest to the overall composition. In production, harmony vocals can be panned (placed at different positions in the stereo field) to create a fuller, wider sound that envelops the listener.

With the right arrangement and blending, harmony vocals help reinforce the melody, enhance the song’s dynamics, and create a more immersive listening experience. They are an essential tool for adding dimension and complexity, turning a simple vocal line into a rich, layered tapestry of sound.

Harry Fox

The Harry Fox Agency, Inc. (HFA), is a US company that issues Mechanical Licenses and collects Mechanical Royalties, on behalf of music publishers, in return for a fee of 11.5%.

The cost of a record company audit is not cheap which makes it impractical for small publishers to carry out, at least on a regular basis. Fortunately, they benefit from regular record company audits conducted but Harry Fox.

HFA stopped issuing synchronization (or synch) licenses (as used for music in advertising, movies, music videos, and television programs).

HFA does collect and distribute monies due on synch licenses that were granted before 2002 when HFA discontinued its synch service.

HFA conducts royalty examinations. They investigate and negotiate new business opportunities, and pursue piracy claims.

Harry Fox is also involved with industry-level negotiations representing the interests of its members.

HDCD

Microsoft music disc format that plays on CD players.

Head Arrangement

A head arrangement is a style of musical arrangement created and developed “in the head” rather than written down in sheet music or notation. This approach is common in jazz and blues and relies on musicians remembering and improvising parts of the arrangement, often collaboratively, rather than following a pre-written score. Musicians perform head arrangements by working out sections like melody, harmony, solos, and structure together in rehearsal, relying heavily on memory and intuition to recreate the piece during performances.

Head arrangements allow for a high degree of improvisation and flexibility, making each performance unique. In jazz, for example, the musicians may start with a basic melody or “head” and build variations around it, with each musician adding their own embellishments, fills, or solos. This approach enables musicians to respond to each other in real-time, creating a dynamic, spontaneous feel that is a hallmark of live jazz performances.

Historically, head arrangements were popular in the big band and swing eras, especially with groups that had limited access to formal written arrangements. Bands would often create and rehearse head arrangements in a relatively short time, adapting to the abilities and strengths of individual band members. This practice allowed musicians to perform and evolve songs quickly, adding new elements or rearranging sections on the spot.

A head arrangement emphasizes creativity and musical chemistry between musicians, often resulting in fresh, lively interpretations of a piece each time it’s performed. This approach continues to be valued today for its spontaneity and the unique energy it brings to live performances.

Headroom

This is the amount of signal amplitude range between the nominal signal level and the signal level at which clipping will occur. Headroom is normally expressed in dB.

Headroom refers to the difference between the loudest peak level of an audio signal and the maximum level that equipment or a recording medium can handle before distorting. In simpler terms, it’s the “safety margin” in volume that prevents unwanted distortion, ensuring clear, high-quality sound without unwanted clipping or crackling.

In audio production, headroom is crucial for maintaining a clean mix. If a track’s volume levels get too close to the maximum (often 0 dB in digital recording), it can cause clipping, which results in harsh, unpleasant sounds. Keeping a few decibels of headroom below this limit provides space for dynamic moments in the track without causing distortion.

For mixing engineers, leaving headroom is essential as they combine multiple tracks. If each track is too close to the peak, the combined levels can easily exceed the limit, leading to distortion. By allowing headroom on each track, engineers can adjust volume and effects without degrading sound quality.

When preparing a song for mastering, engineers often aim to leave a final headroom level around -3 to -6 dB, giving the mastering engineer space to further process and polish the track. This extra headroom is necessary to apply compression, EQ, and limiting without introducing distortion into the final mix.

Headroom isn’t just about preventing distortion; it also helps create a more dynamic, engaging listening experience. By avoiding overly compressed, maxed-out levels, audio can “breathe,” giving space for quieter and louder moments to shine. This balance contributes to a more professional and enjoyable sound across all playback systems, from headphones to high-end speakers.

Headstock

The headstock is situated at the top of the neck. Normally this has the tuning pegs (sometimes called machine heads), and often displays the guitar company logo.

Helmholtz Resonator

This is an acoustic room treatment that can trap a specified range of low-frequency audio signals.

A Helmholtz resonator is an acoustic device designed to resonate at a specific frequency, amplifying certain sounds while reducing others. Named after German physicist Hermann von Helmholtz, this resonator consists of a hollow cavity (such as a bottle or closed box) with a small opening. When air is blown across or into the opening, it vibrates at a natural resonant frequency based on the cavity’s size, shape, and the length and diameter of its neck.

Helmholtz resonators are commonly used in acoustic treatment and sound design. In studios, they help manage low-frequency build up by absorbing specific bass frequencies that can cause muddiness in the sound. They act like a filter that “traps” unwanted low frequencies, allowing for a clearer and more balanced sound in the room. The resonator absorbs sound energy at its tuned frequency, minimizing reflections and preventing sound waves from “booming” or interfering with the overall mix.

In musical instrument design, Helmholtz resonance plays a role in shaping the tone of instruments like guitars, violins, and wind instruments. For instance, the body of an acoustic guitar acts as a Helmholtz resonator, amplifying the sound of the vibrating strings to produce a fuller, richer tone. The resonance of the guitar body helps define its low-end frequency response, contributing to the instrument’s unique voice.

Helmholtz resonators are also found in everyday objects, like when you blow across the top of a bottle and hear a distinct pitch. This pitch is the resonant frequency of that bottle acting as a Helmholtz resonator. By understanding and applying this concept, sound engineers and acousticians can shape environments and instrument sounds with precision.

Hertz (Hz)

This is the unit of measurement for frequency.

1 Hz = 1 cycle/sec

More generally:

Frequency = Wavelength/time

Hertz (abbreviated as Hz) is the unit of frequency measurement, representing the number of cycles or vibrations per second of a sound wave. Named after German physicist Heinrich Hertz, this measurement is used to describe the pitch or frequency of musical notes, ranging from low bass sounds to high treble tones.

In music and audio, frequency is directly related to how high or low a sound is perceived. Lower frequencies produce deep, bass sounds, while higher frequencies create brighter, treble sounds. For instance, a low note on a bass guitar might have a frequency of around 60 Hz, whereas a high note on a violin can reach thousands of Hz.

The human ear typically hears frequencies between 20 Hz and 20,000 Hz (20 kHz). Frequencies below 20 Hz are called infrasound and are generally felt as vibrations rather than heard. Frequencies above 20 kHz are called ultrasound, which is beyond human hearing but can still be perceived by certain animals or used in specialized audio technology.

In audio production, understanding Hz is essential for equalization (EQ) and sound design. Producers and engineers use Hz values to adjust frequencies within a mix, enhancing or reducing specific tones to achieve a balanced sound. For example, boosting frequencies around 80 Hz can add warmth to a bassline, while cutting frequencies above 10 kHz can reduce unwanted hiss in recordings.

The standard tuning for musical instruments typically uses a reference pitch of 440 Hz, representing the note A above middle C. This frequency standard helps musicians tune their instruments consistently, ensuring that music sounds harmonious when played across different instruments and settings.

Hi-Hat

An instrument used as part of a drum kit consisting of a stand, rod, pedal, and 2 cymbals, one on top of the other. As the pedal is raised or lowered it causes the rod running through the stand to raise the top cymbal. Creating different tones as it is struck.

High Fidelity (Hi-Fi)

High fidelity, commonly abbreviated as Hi-Fi, refers to the reproduction of sound with minimal distortion and a high degree of accuracy, closely resembling the original recording. Hi-Fi audio systems are designed to deliver clear, detailed sound that captures the full range of frequencies, from deep bass to sparkling highs, providing listeners with an authentic and immersive listening experience.

Hi-Fi systems aim to avoid audio artifacts like hiss, distortion, or unnatural coloration of the sound. To achieve this level of quality, Hi-Fi equipment—such as speakers, amplifiers, and audio sources—must be carefully designed and often includes high-quality components that can reproduce subtle details and dynamics accurately.

The term Hi-Fi became popular in the 1950s and 1960s, coinciding with advancements in audio technology and the rise of dedicated home audio systems. Hi-Fi setups are often favored by audiophiles—enthusiasts who seek the best possible sound quality and are willing to invest in premium equipment to achieve it.

In contrast, lo-fi (low fidelity) describes audio that may have imperfections or noise, which some artists and listeners find charming or stylistically appealing. Hi-Fi, however, prioritizes a clean, polished sound.

Today, Hi-Fi audio is accessible through a variety of formats and systems, from vinyl records and high-resolution digital files to premium streaming services and surround sound setups. By faithfully reproducing music’s nuances, Hi-Fi systems allow listeners to enjoy a richer, more engaging listening experience, capturing every detail intended by the artist and sound engineers.

High-Pass Filter (HPF)

This is a type of filter that rejects low-frequency audio signals.

A high-pass filter (HPF) is an audio processing tool that allows high frequencies to pass through while reducing or eliminating lower frequencies. Often used in mixing and sound design, high-pass filters help clear up a mix by cutting out unwanted bass frequencies, which can create muddiness or overlap with other elements.

In a high-pass filter, the cutoff frequency determines the point at which low frequencies start being attenuated. For example, setting a high-pass filter with a cutoff at 100 Hz means frequencies below 100 Hz will be gradually reduced, while frequencies above 100 Hz will pass through unaffected. The rate of this reduction, known as the slope (measured in decibels per octave), can vary; common slopes are 6 dB, 12 dB, or 24 dB per octave, with steeper slopes removing bass frequencies more aggressively.

High-pass filters are essential tools in audio production for several reasons:

• Vocals: A high-pass filter is often applied to vocals to remove low-end rumble and unwanted noise, like mic handling sounds or low-frequency environmental noise, allowing the vocal to sit more clearly in the mix.
• Instruments: For instruments that don’t need bass frequencies—such as guitars, cymbals, and synthesizers—a high-pass filter can remove unnecessary low end, making room for bass instruments like kick drums and bass guitars.
• Mastering: In the mastering process, a subtle high-pass filter may be used to remove inaudible low-end frequencies that could muddy the overall track on certain playback systems.

By removing low-end frequencies where they’re not needed, high-pass filters can make mixes sound cleaner, clearer, and more professional, giving each element space to breathe and improving the overall balance of the audio.

Hip-Hop

Hip-hop is a cultural and musical movement that originated in the Bronx, New York, during the 1970s, characterized by four main elements: rap (rhymed spoken word), DJing (manipulating sounds on turntables), breakdancing (a unique street dance style), and graffiti (street art). While it began as a way for marginalized communities to express their experiences, hip-hop has grown into a global phenomenon, influencing everything from music and dance to fashion and language.

Musically, hip-hop centers on rhythmic beats and basslines, often built by DJs who use turntables, drum machines, or digital production software to sample, loop, and layer sounds. Early hip-hop beats were created by isolating the “break” section of a record—a high-energy instrumental part that encouraged dancing—and repeating it. These beats provided the foundation for MCs (rappers) to layer their lyrics, which are often deeply personal, addressing themes of struggle, resilience, social issues, and celebration.

Rap, hip-hop’s most well-known vocal style, is a unique blend of rhythm, rhyme, and storytelling, delivered in a rhythmic, often syncopated flow. Lyrics can vary widely in subject matter, ranging from political and social commentary to party anthems and introspective reflections. Wordplay, metaphor, and cultural references are key to the art of rapping, showcasing both skill and creativity.

As hip-hop spread, it evolved into diverse subgenres, including gangsta rap, conscious hip-hop, and trap, each with its distinct sound and message. Today, hip-hop is one of the most influential music genres worldwide, shaping mainstream music, fashion, and social movements, while continuing to give voice to artists and communities everywhere.

Hiss

Hiss refers to a high-frequency noise often heard as a constant, subtle “shhh” sound in audio recordings or playback. It’s a form of background noise that typically originates from electrical interference within recording equipment, microphones, or audio circuits, especially in analog systems. In digital audio, hiss is less common but can still occur due to electronic noise or issues with gain settings.

Hiss is most noticeable in quieter parts of a recording, such as soft vocals or ambient soundscapes, where the high frequencies are more exposed. Factors that contribute to hiss include high microphone gain, low-quality cables, or aging analog equipment like tape recorders, which naturally introduce a degree of hiss.

In audio production, minimizing hiss is essential for achieving a clean and professional sound. Techniques to reduce or eliminate hiss include:

• Noise Gates: Tools that mute or reduce sound below a certain volume threshold, useful for cutting out background hiss in quiet sections.
• EQ (Equalization): Reducing certain high frequencies can help minimize the prominence of hiss without affecting the overall sound.
• Noise Reduction Software: Digital tools like noise-reduction plugins can isolate and remove hiss from recordings, particularly useful in post-production.

Although often undesirable, some genres (like lo-fi or retro-inspired music) may embrace hiss as part of their aesthetic, using it to add warmth or texture to a track. However, in most professional recordings, reducing hiss is a priority to maintain clarity and quality in the final mix.

Holdback

A period of time where a record cannot be released. This can happen when an artist is signed exclusively to a record company, and another record company wishes the artist to record a track for them (for example a track written for a soundtrack). Exclusivity may be temporarily waived in return for the right to include that track on a greatest hits album. The right to release the soundtrack song on such a greatest hits is normally held back for a period of time after the soundtrack release date so that the soundtrack album is not commercially compromised.

Hook

A hook is a catchy part of a song. Hooks are noticeable and memorable. They are often the words that people know or the melody that listeners find themselves humming. A hook can be lyrical, melodic, harmonic, or rhythmic. Lyrically it is commonly the song title. Often hooks are repeated and so are often found in the song refrain or chorus.

Read the Songstuff article “The Power Of Song Hooks“.

House Music

House music is a genre of electronic dance music (EDM) that originated in Chicago in the early 1980s. Known for its repetitive 4/4 beats, steady basslines, and synthesized melodies, house music quickly became popular in nightclubs and has since evolved into one of the most influential genres in dance music worldwide. Its name is derived from “The Warehouse,” a Chicago nightclub where pioneering DJ Frankie Knuckles helped shape the genre’s early sound.

House music is characterized by a tempo typically ranging from 120 to 130 beats per minute (BPM) and a rhythmic, bass-heavy structure designed to keep people dancing. The beat is driven by a consistent kick drum on every quarter note (a style often called a “four-on-the-floor” beat), with layered elements like hi-hats, claps, and synthesizers creating an infectious groove.

The genre often incorporates elements of soul, funk, and disco, along with vocal samples or hooks that add an emotional or anthemic quality to the music. House music subgenres, such as deep house, tech house, and progressive house, bring unique twists to the core sound, ranging from soulful and jazzy vibes to darker, more minimalist tones.

House music has had a massive impact on global music culture, influencing numerous EDM styles and mainstream pop. Its emphasis on rhythm, groove, and energy makes it a staple in dance clubs and festivals around the world. Known for uniting crowds on the dance floor, house music remains a cornerstone of modern electronic music and an enduring symbol of nightlife culture.

Hum

A low-frequency tone that is normally a multiple of 50Hz or 60Hz. This is because it is often related to the mains power frequency.

See 50 Hz Hum

See 60 Cycle Hum

Hybrid Instrument

A hybrid instrument is a musical instrument that combines features of different types or technologies to create a unique sound and playing experience. Often blending acoustic and electronic elements, hybrid instruments are designed to offer the expressive qualities of traditional instruments alongside the versatility of modern digital features.

Examples of hybrid instruments include acoustic-electric guitars, which combine the natural resonance of an acoustic guitar with built-in pickups and preamps for easy amplification and effects processing. Another example is a digital drum kit with pads that feel similar to acoustic drums but trigger electronic sounds, allowing drummers to experiment with a wide range of sounds beyond standard drum kits.

Hybrid instruments are popular in genres that emphasize innovation and sound design, such as electronic, pop, and experimental music. They allow musicians to access a wider range of tones, effects, and textures, often with features like MIDI connectivity, onboard effects, and programmable sounds.

In addition to performance flexibility, hybrid instruments are ideal for live shows and studio recording, where they can seamlessly switch between acoustic and electronic sounds, creating a dynamic, versatile setup. As music technology advances, hybrid instruments continue to evolve, offering artists new ways to blend traditional musicianship with modern soundscaping tools.

Hypercompression

Hypercompression is an audio processing technique that involves applying excessive compression to reduce the dynamic range of a track. This results in a very loud, flat sound with minimized contrast between the softest and loudest parts of the audio. Hypercompression is often used in the mastering stage to make tracks sound as loud as possible, a trend driven by the “loudness wars,” where producers aim to make songs stand out by maximizing volume.

While hypercompression can make a track sound more intense and powerful, it also has downsides. By flattening the dynamics, hypercompression can strip a song of its natural rise and fall, making it sound overly dense and fatiguing to listen to. Instruments and vocals lose their subtlety, and the overall clarity of the mix may suffer.

Hypercompression is particularly common in certain genres, like pop, rock, and electronic music, where high volume is often prioritized. However, in recent years, audio professionals and listeners alike have become more aware of its drawbacks. Many producers now aim for a balance, using compression to enhance volume without completely sacrificing dynamic range.

When used with care, compression can add energy and polish to a track, but hypercompression should be avoided if the goal is a natural, dynamic sound. Listeners generally appreciate music with more dynamic range, as it feels more spacious and less “squashed,” allowing each element in the mix to breathe.