415 Hz: baroque pitch

A4 = 415 Hz is the convention for baroque music on period instruments. It is almost exactly a semitone below 440, which is convenient: a harpsichord or organ built at 440 can be shifted down a key to play with instruments at 415.

Surviving organs and tuning forks show that real baroque pitch varied widely from place to place; 415 is the modern performers’ agreement, not a historical standard.

• Open the tuner at A = 415 Hz

Which note 415 Hz is at other reference pitches

“In tune” depends on what A4 is tuned to, so the same frequency is a slightly different distance from the nearest note in each tuning.

An octave of notes at A4 = 415 Hz

Middle C to the C above, tuned to this reference, beside the same notes at the 440 standard.

Octaves of 415 Hz

Doubling a frequency raises it an octave and halving lowers it one, so these all have the same note name and the same offset from it.

• 51.88 Hz · A♭1
• 103.75 Hz · A♭2
• 207.50 Hz · A♭3
• 830.00 Hz · A♭5
• 1660.0 Hz · A♭6
• 3320.0 Hz · A♭7

Harmonics of 415 Hz

A real instrument playing 415 Hz also sounds whole-number multiples of it. The first eight, and the notes they fall nearest:

Period and wavelength

One cycle of 415 Hz lasts 2.410 milliseconds; in air at 20 °C, where sound travels at about 343 metres a second, one wavelength is 82.7 centimetres.

Convert another frequency

Or hold 415 Hz as a steady tone, sweep from it, or beat it against a second tone in the tone generator. The note frequency chart lists every note from C0 to B8.

Frequently asked questions

Related frequencies

• 440 Hz — the standard tuning pitch
• 430 Hz — a period tuning pitch
• 432 Hz — an alternative tuning pitch