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Piano note

C♯3 138.59 Hz

C♯3 is piano key 29 of 88, MIDI 49, at 138.59 Hz. It sits in the low middle, with guitar open strings and left-hand piano.

  • Key 29 of 88
  • MIDI 49
  • -20 semitones from A4

C♯3

Frequency, piano key and harmonics

C♯3 is piano key 29 of 88, MIDI 49, at 138.59 Hz. It sits in the low middle, with guitar open strings and left-hand piano.

Frequency138.59 HzA4 = 440
MIDI49
Piano key29 of 88
From A4-20 st
Period7.215 ms
Wavelength2.47 m343 m/s
HarmonicFrequencyNearest equal-tempered note
1 · fundamental138.59 HzC♯3 (+0 ¢)
2×277.18 HzC♯4 (+0 ¢)
3×415.77 HzG♯4 (+2 ¢)
4×554.37 HzC♯5 (+0 ¢)
5×692.96 HzF5 (−14 ¢)
6×831.55 HzG♯5 (+2 ¢)

Piano playback uses the nearest piano sample, played faster or slower, plus a sine wave at the exact pitch. The sine button is the exact equal-tempered frequency. Neighbors: C3 and D3. Arbitrary pitches and alternate A4 tunings belong on the calculator.

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Hear the note. Then name the interval.

Interval and chord drills in the app are built on this same piano and this same tuning.

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Explore the cluster

C3 One semitone down. Lower neighbor → D3 One semitone up. Upper neighbor → Note calculator Retune A4 or type any frequency. Open calculator →

FAQ

C♯3 questions

What frequency is C♯3?

138.59 Hz when A4 is 440 Hz. Change the reference on the note calculator if you need another tuning. This page does not change.

What MIDI note is C♯3?

MIDI 49. Piano key 29, counting A0 as key 1 and C8 as key 88.

How loud should I listen?

Keep the tone at a conversation level. These pages can generate steady tones and noise, which fatigue your ears faster than music. If anything rings or feels uncomfortable, stop and turn the volume down.