## Polyrhythms..

steevio
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Atheory wrote:
3 x 5 = 15....so there will be 15 pulses or spaces for a beat. in a 16step sequencer the last one is cut off or not used. so.....
it's interesting that 16 step sequencers are not good for polyrhythms generally.
say you want a 5 against 4 polyrhythm, you need 20 steps.

i regularly use 5 against 4 against 3 polyrhythms in my music, and the number 16 just doesnt come into it.

the magic numbers for working polyrhythmically (at least with 3/4/5) are 15 bars, 30 bars, 60 bars.

its interesting that we divide time up in this way and also the degrees of a circle.
to me its much more natural than dividing things up into 8 /16 etc. it locks you into 4/4.

if you bring 7 into the equation, then you have to have 105 bars to keep the polyrhythms cycling.

Atheory
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yeah it is really interesting about the step sequencer thing, one work around i guess is to shorten the pattern on your sequencer to say 7 pulses for one of the hits, and to five for another. i guess that works ok.

but i think its nice also to have a concrete idea of where the notes are meeting with each other, so maybe a DAW or something is good for that bigger picture.

steevio
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Atheory wrote:yeah it is really interesting about the step sequencer thing, one work around i guess is to shorten the pattern on your sequencer to say 7 pulses for one of the hits, and to five for another. i guess that works ok.

but i think its nice also to have a concrete idea of where the notes are meeting with each other, so maybe a DAW or something is good for that bigger picture.
yeah thats what i meant really, the bigger picture, how do things play out over bar resolution sequences, say you have a 7 step sequence running and you dont want it just to constantly repeat 7 notes, you might want variations that happen in a 21 note sequence so that it relates to a 3 step pattern,
its harder to play around with the mathematics and have fun with polyrhythms with very short sequences, and it quickly becomes repetitive.

in a minimal context, you have to subtract the unnecessary notes and leave the ones in that create interesting rhythmic combinations, otherwise you are effectively making trance.
usually these interesting confluences happen outside the limitations of 16 step sequences.

Martian Telecom
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The value of a quarter note pulse does not change. It doesn't matter how many pulses there are in the bar. I used quarter notes because it is a very easy way to show how the bars cycle against each other.

2/4 over 3/4 =

1 - 2 - 1 - 2 - 1 - 2
1 - 2 - 3 - 1 - 2 - 3 and this pattern can cycle on forever

3/4 over 5/4 =

1 - 2 - 3 - 1 - 2 - 3 - 1 - 2 - 3 - 1 - 2 - 3 - 1 - 2 - 3
1 - 2 - 3 - 4 - 5 - 1 - 2 - 3 - 4 - 5 - 1 - 2 - 3 - 4 - 5.......

We are basically saying the same thing and notating it differently.

And the secret to dealing with short phrases and repetition it to use multiple patterns and switch them frequently. I use hardware and the way that I make it work it to run 4 sequencers in different signatures at the same time and have them switch patterns. You aren't able to see it on the screen but I think there is something to be said for being forced to use your ears.

The MMT8 is great for stuff like this because you can cut and paste patterns into other patterns. Once you have done that you can change the length of the pattern from one quarter note to 99. I usually cut things up into 32 or 64 beat patterns because it makes it easier to arrange things and have the polyrhymic stuff lock to the 4/4 arrangement.

I do song oriented music and I like being able to have everything drop on a dime and go into another song section. Being able to paste 4 different 3/4 patterns into one long pattern and then chop it to size is nice. It is the one "secret" feature that most people never take advantage of.

I generally try to keep the poly stuff away from the foot of the track. I try to keep my kicks, hats and bass lines 4/4 and then use polyrhythm for percussion and synth stuff like stabs and leads. This makes things more complex but keeps things from getting overly noodly/proggy.

steevio
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Martian Telecom wrote:The value of a quarter note pulse does not change. It doesn't matter how many pulses there are in the bar. I used quarter notes because it is a very easy way to show how the bars cycle against each other.

2/4 over 3/4 =

1 - 2 - 1 - 2 - 1 - 2
1 - 2 - 3 - 1 - 2 - 3 and this pattern can cycle on forever

3/4 over 5/4 =

1 - 2 - 3 - 1 - 2 - 3 - 1 - 2 - 3 - 1 - 2 - 3 - 1 - 2 - 3
1 - 2 - 3 - 4 - 5 - 1 - 2 - 3 - 4 - 5 - 1 - 2 - 3 - 4 - 5.......

We are basically saying the same thing and notating it differently.

And the secret to dealing with short phrases and repetition it to use multiple patterns and switch them frequently. I use hardware and the way that I make it work it to run 4 sequencers in different signatures at the same time and have them switch patterns. You aren't able to see it on the screen but I think there is something to be said for being forced to use your ears.

The MMT8 is great for stuff like this because you can cut and paste patterns into other patterns. Once you have done that you can change the length of the pattern from one quarter note to 99. I usually cut things up into 32 or 64 beat patterns because it makes it easier to arrange things and have the polyrhymic stuff lock to the 4/4 arrangement.

I do song oriented music and I like being able to have everything drop on a dime and go into another song section. Being able to paste 4 different 3/4 patterns into one long pattern and then chop it to size is nice. It is the one "secret" feature that most people never take advantage of.

I generally try to keep the poly stuff away from the foot of the track. I try to keep my kicks, hats and bass lines 4/4 and then use polyrhythm for percussion and synth stuff like stabs and leads. This makes things more complex but keeps things from getting overly noodly/proggy.
i still dont think your diagram explains polyrhythm to a beginner. sorry

Some Definitions of Poly rhythms:

First definition:
To qualify as a poly rhythm, the contributing rhythms should be chosen such that the numbers denoting their rhythmic relation, are relatively prime to each other.
Second definition:
If the sum of two (or more) simultaneously sounding rhythms results in a subdivision of the beat that is not present in either of the constituting rhythms, we call this resultant rhythm poly rhythmic.
Third definition:
Two different rhythmic patterns do not result in a poly rhythm (when played simultaneously), when one of those rhythms can be contained in the subdivision of the beat that is implied by the other rhythm.

if you take a simplified version of your diagram and place it next to ATheories or mine (which are the standard ways of notating polyrhythm) they are just not compatible;

3 against 4;

yours;
1 - 2 - 3 - 1 - 2
1 - 2 - 3 - 4 - 1

polyrhythm;
1 - - 2 - -3 - - 1
1 - 2 - 3 - 4 - 1

they cant both be right bro.
Last edited by steevio on Mon May 04, 2009 11:06 am, edited 2 times in total.

mazee
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Ok, so I made a (pretty lame) test... The first percussion part is in 9/8, the second is in 5/4 and then they're joined by a standard 4/4 drum part. The parts all "slip" in relation to each other, which I think must be it...

I'm pretty excited about the possibility of using this for melodic and other parts. Am I right in saying that you probably have to go through and edit those parts bar by bar so that they don't clash etc?

The other question I have is about time signatures. The first number in, say, "7/8" expresses how many beats there are per bar, and I guess the second expresses the length of those beats, e.g. eighth notes, quarter notes etc. Is there ever a time when that second number isn't a multiple of 2, i.e. 2,4,8,16 etc? It's just that I've been experimenting with making polyrhythms by changing logic's time signature to make each different part, but it won't allow me to use anything other than 2,4,8,16 etc. for the second number. Do signatures of e.g. 5/7 exist, and if they do, could you construct useful polyrhythms with them? I've read the wikipedia article, but it is fairly confusing...

Cheers for all your help so far, guys.

tone-def
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mazee wrote:I'm pretty excited about the possibility of using this for melodic and other parts. Am I right in saying that you probably have to go through and edit those parts bar by bar so that they don't clash etc?
it depends if you like the clash or not. Sometimes you might want to change the note velocity if your got lots of notes all hitting at the same time. Those points are also good for making slight variations in the groove.

alexx.wolfe
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Reading this thread I realized that I know nothing about music production... Instinct it the only tool I have
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