I have become quite a fan of metronomes/click tracks as a result of working within Studio One. I've also discovered something that I'm sure isn't a huge revelation to anyone. As soon as you get out of 4/4 time the metronome no longer works as I would like it to work. In other words, I can no longer count on it.
If you work with 4/4 time at 60 beats per minute, you would expect to hear 60 beats after one minute. That works out to 15 bars of 4 beats 15 x 4 = 60. In fact it does exactly that. That's one beat per second or 4 seconds for one bar or 15 bars per minute.
Now, let's change the time signature to 12/8 and keep 60 beats per minute, you get 2x the number of beats per minute, assuming that you count 1 & a 2 & a 3 & a 4 & a each as individual beats. You get two beats per second, so we are no longer looking at 60bpm even though the metronome says we are. While our beats are twice as fast as 60bpm it now takes 6 seconds for 1 bar or 60 seconds for 10 bars. At 12 beats per measure, that's 120 beats per minute or twice what we get in 4/4 timing at 60bpm.
Set the timing to 12/8 and halve the tempo to 30 beats per minute. That will put us right on a tempo that is comparable to 4/4 at 60 beats per minute. If we count it like is usually done in blues, (basically triplet feel 4/4 time), we count 1 & a 2 & a 3 & a 4 & a only counting the number as beats. This actually gives us 20 counted beats or 5 bars of music (in 12/8 time).
Confused yet? Wait, it gets better. If we set the time signature to 12/8 and the tempo to 90 beats per minute, and use a blues style metric (meaning only the numbers are beats) 1 & a 2 & a 3 & a 4 & a we then get 60 numbered beats in one minute or 15 measures.
What does this matter? It probably doesn't, but this has been one of those things that makes me scratch my head, reach for whiskey and say, "WTF?"
If you work with 4/4 time at 60 beats per minute, you would expect to hear 60 beats after one minute. That works out to 15 bars of 4 beats 15 x 4 = 60. In fact it does exactly that. That's one beat per second or 4 seconds for one bar or 15 bars per minute.
Now, let's change the time signature to 12/8 and keep 60 beats per minute, you get 2x the number of beats per minute, assuming that you count 1 & a 2 & a 3 & a 4 & a each as individual beats. You get two beats per second, so we are no longer looking at 60bpm even though the metronome says we are. While our beats are twice as fast as 60bpm it now takes 6 seconds for 1 bar or 60 seconds for 10 bars. At 12 beats per measure, that's 120 beats per minute or twice what we get in 4/4 timing at 60bpm.
Set the timing to 12/8 and halve the tempo to 30 beats per minute. That will put us right on a tempo that is comparable to 4/4 at 60 beats per minute. If we count it like is usually done in blues, (basically triplet feel 4/4 time), we count 1 & a 2 & a 3 & a 4 & a only counting the number as beats. This actually gives us 20 counted beats or 5 bars of music (in 12/8 time).
Confused yet? Wait, it gets better. If we set the time signature to 12/8 and the tempo to 90 beats per minute, and use a blues style metric (meaning only the numbers are beats) 1 & a 2 & a 3 & a 4 & a we then get 60 numbered beats in one minute or 15 measures.
What does this matter? It probably doesn't, but this has been one of those things that makes me scratch my head, reach for whiskey and say, "WTF?"