Math Is Fun Forum

jp

Member

Registered: 2011-07-29

Posts: 1

music math word problem (permutations and combinations)

Hi, I am looking for a formula to figure out the different combinations of a four stroke rudiment across a five piece drum set.  The rudiment is a set pattern that doesn't per-mutate at all.  The combinations are with the different striking surfaces of the drums themselves.  So if I had a pattern like r,l,r,l and I can start on any drum, how many different combinations can I come up with before I exhaust the combinations with the five different drums?  I don't have a good formula for this.  Any ideas??

JP

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: music math word problem (permutations and combinations)

Hi jp;

Welcome to the forum!

Are you saying that the order r, l, r, l must be preserved across the 5 drums? Then it is simple.

That is if I understand the problem correctly, here is one arrangement.

l   r  l   r
1 2 3 4 5    drums

But if the order of the drums counts then there is 120 x 5 = 600 ways. Can I get a little bit more information?

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