Quote:
The guitars were recorded one whole step up (A) at a faster tempo.
So how would you find out what the original tempo of the "A" guitars was in order to arrive at the "G" guitars in the final result?
|
Well, if you hate math, you're gonna really hate this answer!
The difference between any given note and the note ONE octave above it is a ratio of 1:2. To determine the frequency of the octave above "A-440" you multiply by two. The answer is "A-880".
That means the the distance between the notes in an octave is 1/12th of the 1:2 ration... or the 12th ROOT of 2.
So, if you're in the key of G, and you want to know the tempo of the key of A... all you do is multiply the tempo of the key of G by the 12th root of 2 for each 1/2 step.
If the 12th root of 2 is 1.059463 (it is), then if you are in the tempo "quarter note = 120 bpm" in the key of G... the tempo in the key of A will be figured like this: 120 bpm x 1.059463= the tempo of the key of G# or 127.13556 bpm. Then 127.13556 bpm x 1.059463 = the tempo of the key of A or 134.69542 (approximately, of course).
If you're goin' the other way: If A is 120 bpm... then A flat tempo will be 120 divided by 1.059463 or 113.26492 and then the key of G tempo is 113.26492 divided by 1.059463 or 106.90785 (approximately).
1.059463... The twelth root of two... our musical friend.