Musical notes have no absolute frequency range because note names repeat across octaves. Practical ranges include 27.50–4,186.01 Hz for an 88-key piano and approximately 8.18–12,543.85 Hz for MIDI notes 0–127, assuming 12-tone equal temperament with A4 set to 440 Hz.
Frequency is measured in hertz (Hz), or vibration cycles per second. A note’s fundamental usually determines its perceived pitch, while harmonics shape its character. For values organized by octave, see the music note frequency chart.
What Is the Frequency Range of Musical Notes?
The frequency range of musical notes depends on the system being measured. A piano, a human voice, the MIDI standard, and the full range of theoretically named notes all have different lower and upper limits.
Common musical-note ranges at a glance
| Reference system | Lowest note and frequency | Highest note and frequency | What the range represents |
|---|---|---|---|
| Standard 88-key piano | A0, 27.50 Hz | C8, 4,186.01 Hz | A widely used acoustic and notation reference |
| MIDI notes 0–127 | C−1, about 8.18 Hz | G9, about 12,543.85 Hz | The complete MIDI note-number range under one common octave convention |
| Typical human hearing | About 20 Hz | About 20,000 Hz | An approximate auditory range, not a musical-note limit |
| Theoretical note system | No fixed minimum | No fixed maximum | Note names can extend through additional octaves |
The commonly cited 20 Hz to 20 kHz hearing span is an estimate, not a musical-note limit. Sensitivity varies by person and age. The human hearing frequency range also includes sounds that are not perceived as distinct pitches.
Why there is no absolute lowest or highest musical note
Western note names repeat from A through G, with sharps or flats between most neighboring natural notes. Moving up one octave doubles frequency; moving down an octave halves it. Extremely low frequencies may be felt as pulses, while extremely high frequencies can exceed human hearing. Practical limits therefore come from hearing, instruments, equipment, and notation—not note naming.
What Frequencies Do Notes Have Across the Octaves?
Each octave covers a two-to-one frequency ratio. C5 has twice the frequency of C4, while C3 has half the frequency of C4. The note identity remains C because an octave is treated as a repetition of the same pitch class at a different register.
C-note frequencies from C0 through C8
The following values assume A4 = 440 Hz and 12-tone equal temperament:
| Note | Frequency |
| C0 | 16.35 Hz |
| C1 | 32.70 Hz |
| C2 | 65.41 Hz |
| C3 | 130.81 Hz |
| C4, middle C | 261.63 Hz |
| C5 | 523.25 Hz |
| C6 | 1,046.50 Hz |
| C7 | 2,093.00 Hz |
| C8 | 4,186.01 Hz |
Middle C is usually C4 in scientific pitch notation, though some software uses different octave-numbering conventions. The frequency remains the reliable identifier: middle C’s frequency is approximately 261.63 Hz when A4 equals 440 Hz.
A-note frequencies from A0 through A8
The A notes make octave doubling easy to see:
| Note | Frequency |
| A0 | 27.50 Hz |
| A1 | 55.00 Hz |
| A2 | 110.00 Hz |
| A3 | 220.00 Hz |
| A4 | 440.00 Hz |
| A5 | 880.00 Hz |
| A6 | 1,760.00 Hz |
| A7 | 3,520.00 Hz |
| A8 | 7,040.00 Hz |
A4 is the usual tuning reference, often called concert A. It means every equal-tempered note is calculated relative to A4—not that every instrument is tuned directly to 440 Hz. The guide to A4 frequency explains this reference in more detail.
What Is the Frequency Range of a Piano?
A standard 88-key piano spans A0 at 27.50 Hz to C8 at approximately 4,186.01 Hz. This range covers seven full octaves plus a minor third and is commonly used as a practical reference for the span of pitched music.
Lowest and highest notes on an 88-key piano
A0 at 27.50 Hz lies above the commonly cited 20 Hz hearing boundary. The lowest piano notes can still sound less clearly pitched because upper harmonics help the ear identify them.
C8’s fundamental is about 4.19 kHz, but its harmonics extend higher. A complete piano note frequency reference lists all 88 keys.
Why a piano is a useful but incomplete reference
The piano covers more pitches than many acoustic instruments, and its keyboard presents semitones clearly. However, organs, synthesizers, and transposed digital instruments can extend beyond it. A piano represents a broad practical range, not the boundary of musical sound.
How Do Instrument and Voice Frequency Ranges Compare?
Instrument and voice ranges should be compared by their fundamentals, not by their complete sound spectra. A singer producing A3 has a fundamental near 220 Hz, but the voice also contains harmonics at higher frequencies that shape its tone.
Endpoints vary with instrument design, tuning, technique, and performer. A standard-tuned guitar has open strings from E2 at about 82.41 Hz through E4 at about 329.63 Hz, while fretted notes extend higher. Compare individual strings in the guitar note frequency guide.
Human voices also resist rigid limits. Voice types such as bass, tenor, alto, and soprano describe more than extreme notes; tessitura, the comfortable working range, also matters.
Fundamental frequency versus the full sound spectrum
The fundamental is the lowest repeating frequency of a periodic tone. Harmonics occur at whole-number multiples: a 100 Hz tone may contain energy near 200, 300, 400 Hz, and beyond.
This explains why a recording contains frequencies above its highest played note. A violin note with a 1,000 Hz fundamental may produce harmonic energy at several kilohertz, making the audio spectrum wider than its range of fundamentals.
How Are Musical-Note Frequencies Calculated?
In 12-tone equal temperament, frequency is (f=440\times2^{n/12}), where (n) is the semitone distance from A4. Positive values move upward; negative values move downward.
Worked example: calculating middle C
C4 is nine semitones below A4, so (n=-9):
[
f=440\times2^{-9/12}\approx261.63\text{ Hz}
]
The factor (2^{1/12}), approximately 1.05946, is the ratio between adjacent equal-tempered semitones. After 12 steps, the ratio is exactly 2, producing the next octave. The guide to frequency in music connects these vibration rates with perceived pitch.
What happens when the tuning reference changes?
Changing A4 changes every calculated note by the same proportion. If A4 is set to 432 Hz rather than 440 Hz, middle C becomes approximately 256.87 Hz instead of 261.63 Hz.
The note names and intervals do not change; the whole system shifts lower. A frequency table is therefore only complete when it states its reference pitch and tuning system.
Are Musical Notes Limited to the Human Hearing Range?
Notes can be defined below 20 Hz or above 20 kHz, but humans may not hear them as pitches. Low vibration may be sensed as pulses or movement; frequencies above hearing are ultrasonic.
A note near a hearing limit may still be inferred from audible harmonics. Playback equipment matters too: a speaker may reproduce the harmonics but not a very low fundamental. Mathematical frequency, playable pitch, and audible sound are related but not identical. The scientific pitch notation guide decodes labels such as A0, C4, and G9.
Frequently Asked Questions
What is the lowest frequency considered a musical note?
There is no universal lowest musical-note frequency because note names can continue into lower octaves mathematically. In practical hearing, frequencies below roughly 20 Hz are more likely to be felt as individual pulses or vibration than heard as a stable pitch.
What frequency range does an 88-key piano cover?
A standard 88-key piano ranges from A0 at 27.50 Hz to C8 at approximately 4,186.01 Hz. Those figures assume A4 = 440 Hz and 12-tone equal temperament.
What musical note is 440 Hz?
In standard concert pitch, 440 Hz is A4, the A above middle C. It serves as the reference from which the frequencies of other equal-tempered notes are calculated.
Why does every octave double in frequency?
An octave corresponds to a frequency ratio of 2:1. A waveform vibrating twice as fast produces a pitch one octave above, so 220 Hz, 440 Hz, and 880 Hz are all A notes in consecutive octaves.
Can musical notes exist below 20 Hz or above 20,000 Hz?
Yes, note names can be assigned to frequencies outside typical human hearing. Those notes may not be directly audible to people, although infrasound may be felt and audible harmonics may reveal a low fundamental.
Does changing from A4 = 440 Hz to A4 = 432 Hz change every note?
Yes. Changing the A4 reference rescales every note in the tuning system by the same ratio; for example, C4 changes from about 261.63 Hz at A4 = 440 Hz to about 256.87 Hz at A4 = 432 Hz.
Vincent is a pitch detection and vocal analysis writer at OnlinePitchDetector. He focuses on pitch recognition, vocal frequency analysis, singing tools, and real-time audio testing for singers, musicians, producers, and beginners.