I've been developing my internal clock over the years, although I still have a lot of growing to do (don't we all?).
A few years ago, I came up with a way to get myself "in the ballpark" when it comes to counting off tempos. While performing on stage, it can be tough trying to find the right tempo, especially if the songs segue from one to another or if the previous song's tempo is radically different than the one your about to count off. Your mind can really play tricks on you when the pressure is on ... so here's a little method I came up with to help develop my internal clock.
First of all, we need to understand the term bpm. BPM stands for "beats per minute" and is the standard when dealing with tempo and/or metronome markings.
Mathematical Internal Metronome
A good place to start is with 60 bpm. We know that there are 60 seconds in a minute, so if you count off a tune that is 60 bpm (note value is irrelevant at this point) ... you would count off one beat every second. Make sense? If this is breeze easy for you, just bare with me for a moment.
We've all (if you haven't, you should) learned how to count out seconds ... "one thousand one, one thousand two" etc. If you can do this, and really feel where 60 bpm is, you'll quickly be able to count off a number of other tempos ... all with your 60 bpm reference.
Try patting your foot at 60 bpm, checking yourself with a metronome or clock if need be.
Now, to figure out what 120 bpm is, you would simply divide the beat that you are tapping with your foot. This means that if your foot is tapping quarter-notes at 60 bpm, you count, clap or click twice as fast ... thus playing eighth-notes. This basically means that we are now playing two beats every second; 2 clicks multiplied by 60 (seconds in a minute) we get 120 bpm.
You could do the same thing by thinking of sixteenth-notes against the quarter-note tapping at 60 bpm. Doing this would give you 240 bpm because there are 4 sixteenth-notes within a quarter-note; 4 clicks multiplied by 60 (seconds in a minute) equals 240 bpm. Well I don't know about you, but I don't play too many songs at this brisk of a tempo. So let's figure out some tempos that are a bit slower and more radio friendly.
Continue tapping your 60 bpm with your foot. Now count quarter-note triplets, assuming your foot is tapping quarter-notes at 60 bpm. What do you get? How about 90 bpm? Pretty cool huh?! What you are doing is playing three clicks for every two pats of your foot, or six clicks for every four pats ... which is the same thing as 3:2 (three against two) ... which is a polyrhythm. So to summarize, you'll get 90 bpm if you count 3:2 ... assuming that you are patting your foot with a steady flow of 60 bpm. If you can do this, then it will be really easy for you to get 180 bpm ... just count eighth-note triplets against your steady 60 bpm and voila!
Want more? How about 80 bpm? Count 4:3 (four against three) with the three being your 60 bpm in the foot. If you don't have a good grasp of polyrhythms this may be a little tough. A simple way to achieve the 4:3 is to pat your foot as normal, count sixteenth-notes with your mouth, and clap every third note. It would look something like this:
1 e & u 2 e & u 3 e & u
Clicking the bold counts while continuing patting your 60 bpm in the foot will not only give you 4:3, but you'll be clicking 80 bpm.
We can take thisfurther and further using half-note figures, as well as quintuplets, septuplets, etc.
Quick example: Eighth-note quintuplets clicked/played against your 60 bpm foot will give you 300 bpm. If you can click quarter-note quintuplets or 5:2 you'll have 150 bpm.
And you thought you'd never use math outside of high school?
Enjoy!
