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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

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@EvanHahn

EvanHahn Sep 2, 2013

What's the licensing on this?

EvanHahn commented Sep 2, 2013

What's the licensing on this?

@cristiano-belloni

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@1j01

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1j01 commented Feb 19, 2015

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