# How to determine the time signature of a polyrhythm with two parts?

The band Meshuggah has a straightforward approach to polyrhythms. There's also a base which is 4/4 and then some other count which plays N times then repeats exactly on the 1 of the base. it'll be clearer with example:

3 bars of 7 plus 4 == 32 total hits 3 bars of 9 + 5 == 32 total hits

Would the first be 7/4, 7/32, or what? Same with the second.

• You example isn't clear to me. Do the "32 total hits" occupy one base unit of 4/4, or eight units - i.e. 32 beats? Also, "3 bars of 7 + 4" doesn't add up to 32 on my calculator! (I make it 25 beats not 32).
– user19146
Apr 4, 2017 at 4:19
• I assume you mean 4 bars of 7 plus 4? Apr 4, 2017 at 5:10
• @alephzero yeah my mistake on the 7/4 thing. As to whether 32 'base unit' that is part of the question and i should have specified. From my understanding it differs between songs - usually it's eighths, sixteenths, or their triplet variants right? How would that effect the resulting signature on paper? Apr 4, 2017 at 5:18
• I would call this example "polymetry". Polyrhythm is the other end of the spectrum of two (or more) different beats going at once. For instance, if you had seven beats in one voice played in the same amount of time as four beats in the other, that would be polyrhythm. If the beats are the same length, but combined into different meters, say seven bars of four against four bars of seven (similar to your example), that's polymetry. May 4, 2017 at 20:01