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D♯2 / E♭2 · 77.78 Hz

D♯2 is piano key 19 of 88 and MIDI note 39 - the bass register, where bass lines and a male bass voice live. Play the pure tone below, tune to it, or explore the note in every octave.

77.78Hz

Volume50%

Waveform

D♯2 at a glance

Frequency

77.78 Hz

Wavelength (in air)

4.41 m

MIDI note

39

Piano key

19 / 88

Octave

2

Enharmonic

E♭2

All values assume twelve-tone equal temperament at the international standard pitch of A4 = 440 Hz. In that system every semitone has the same size - a frequency ratio of 2^(1/12) - so D♯2 is exactly 440 × 2^(-30/12) Hz. Under alternative references the note shifts with the reference: at A4 = 432 Hz, D♯2 becomes 76.37 Hz.

D♯ in every octave

Note	Frequency	MIDI	Piano key
D♯1	38.89 Hz	27	7
D♯2 ←	77.78 Hz	39	19
D♯3	155.56 Hz	51	31
D♯4	311.13 Hz	63	43
D♯5	622.25 Hz	75	55
D♯6	1244.5 Hz	87	67
D♯7	2489.0 Hz	99	79

Each octave doubles the frequency - the simplest relationship in music, and the reason notes an octave apart sound like “the same note, higher”.

Neighboring notes

C♯2 · 69.30 Hz D2 · 73.42 HzD♯2 · 77.78 HzE2 · 82.41 Hz F2 · 87.31 Hz

One semitone down is D2 at 73.42 Hz; one semitone up is E2 at 82.41 Hz. Need a frequency between notes, or a different waveform? The tone generator plays anything from 20 Hz to 20 kHz; the note ↔ frequency converter does the math both directions, and the chromatic tuner listens to your instrument and shows the offset in cents.

D♯2 FAQ

What frequency is D♯2?

D♯2 / E♭2 is 77.78 Hz in twelve-tone equal temperament with the standard reference of A4 = 440 Hz. Every semitone step multiplies the frequency by the twelfth root of two (about 1.0595), and D♯2 sits 30 semitones below A4.

What MIDI number and piano key is D♯2?

D♯2 is MIDI note 39 and key 19 of 88 on a standard piano. Octave numbering follows scientific pitch notation, where middle C is C4 (MIDI 60).

How do I tune to D♯2?

Play the tone above and match your instrument by ear until the beating between the two pitches slows and disappears, or use the chromatic tuner with your microphone for a cents readout. Small mistunings show up as slow beats: one beat per second at this pitch means you are about 22.1 cents off.

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