Skip to content

Instantly share code, notes, and snippets.

Embed
What would you like to do?
Convert note to frequency
// Takes string of Note + Octave
// Example:
// var frequency = getFrequency('C3');
var getFrequency = function (note) {
var notes = ['A', 'A#', 'B', 'C', 'C#', 'D', 'D#', 'E', 'F', 'F#', 'G', 'G#'],
octave,
keyNumber;
if (note.length === 3) {
octave = note.charAt(2);
} else {
octave = note.charAt(1);
}
keyNumber = notes.indexOf(note.slice(0, -1));
if (keyNumber < 3) {
keyNumber = keyNumber + 12 + ((octave - 1) * 12) + 1;
} else {
keyNumber = keyNumber + ((octave - 1) * 12) + 1;
}
// Return frequency of note
return 440 * Math.pow(2, (keyNumber- 49) / 12);
};
@EvanHahn

This comment has been minimized.

Copy link

commented Sep 2, 2013

What's the licensing on this?

@cristiano-belloni

This comment has been minimized.

@1j01

This comment has been minimized.

Copy link

commented Feb 19, 2015

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
You can’t perform that action at this time.