Polyrhythms and Polymeters in the Grid
Tutorial | Jan 11, 2024
In this video, I explain the difference between Polyrhythms and Polymeters. Polyrhythms involve subdividing a one-bar grid into equally spaced steps using triggers, while in Polymeters, the subdivisions stay the same but the length of the bar changes. To achieve Polymeters, I demonstrate using a reset module to reset the face signal at a certain point in time.
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In this video, I'm summarizing the differences between Polyrhythms and Polymeters, using Bitwig's grid and an oscilloscope module for demonstration. Here are the key points:
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Polyrhythms:
- Created using a "triggers" module in the grid, subdividing a bar into equally spaced steps.
- For instance, subdividing a bar into four steps and then into three creates different rhythmic patterns within the same bar length.
- Demonstrated with note clips showing different subdivisions (like three and five steps) within a single bar, creating varying trigger points.
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Polymeters:
- Differ from polyrhythms in that the subdivision remains constant, but the length of each bar changes.
- Example: subdividing a bar into 16 steps, then changing the bar's length.
- Demonstrated using an "attenuate" module initially, but corrected to use a "phase reset" to maintain the original playback speed.
- The phase is reset at a specific point, altering the loop point within the bar but keeping the subdivision constant.
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Implementation in Bitwig:
- For polymeters, the technique involves comparing the phase signal to a value and using it to reset the phase at a particular point.
- This allows the pattern to loop at different positions within the bar.
- The "triggers" module is identified as a polyrhythm device, while a "reset module" is suggested for creating polymeters.
This tutorial aims to clarify these complex rhythmic concepts and their implementation in music production.
Questions & Answers #
Maybe you dont watch the video, here are some important takeaways:
How are Polyrhythms and Polymeters different? #
Polyrhythms refer to subdividing a one-bar length into equally spaced steps using triggers, while Polymeters change the length of the bar but keep the subdivisions the same. In Polyrhythms, the system length remains constant, while in Polymeters, the length changes but the subdivisions stay the same.
What is the process for creating Polyrhythms? #
To create Polyrhythms, the one-bar length is subdivided into equally spaced steps using a triggers module. By adjusting the number of triggers or subdivisions, the rhythm pattern can be changed. These rhythms can then be represented visually in a note clip.
How are Polymeters created in the grid? #
Polymeters involve keeping the subdivisions of a bar the same while changing the length of the bar. This can be achieved by using a reset module to reset the face of the grid at a specific point in time, allowing for different patterns and positions within the bar.
What is the difference between the playback speed and playback length in Polymeters? #
In Polymeters, adjusting the playback length, for example, making it a third of the initial length, also affects the playback speed. To change the playback length without altering the playback speed, a face reset module can be used to reset the face of the grid at a specific point in time, maintaining the same playback speed but changing the length of the bar.
Transcription #
This is what im talking about in this video. The text is transcribed by AI, so it might not be perfect. If you find any mistakes, please let me know.
You can also click on the timestamps to jump to the right part of the video, which should be helpful.
[00:00:00] So this will be a hard video for me to explain actually my poor English to you.
[00:00:05] The difference between Polyrhythms and Polymeters, but I try my best.
[00:00:10] So inside of the grid we have triggers, which is basically a Polyrhythm device.
[00:00:16] If we take an oscilloscope and face module here, I can explain to you what happens.
[00:00:25] So the face of the grid at the moment, yes, exactly one bar long.
[00:00:30] You can see this on the left side here with the device face.
[00:00:33] So this ramp represents basically exactly one bar.
[00:00:38] And we can now use the triggers module to subdivide this one bar into equally spaced steps.
[00:00:45] So maybe let's use here a second one.
[00:00:49] So with four here, the number four, we subdivided this one bar into four equally spaced steps.
[00:00:57] If we go down to three here, we subdivide this one bar into three equally sized steps.
[00:01:03] If we use multiple of these, let's say here five and here three, and then combine them, we have basically a Polyrhythm.
[00:01:13] So the length of the system is always the same, stays always the same.
[00:01:18] It's exactly one bar, but the subdivisions change.
[00:01:22] If we want to look at this here inside of the note clip, we can say we have one bar.
[00:01:30] So this note is exactly one bar long.
[00:01:33] And then we use it to repeat on the left side and say we subdivide this one bar into three equally spaced steps.
[00:01:40] So that's exactly what we did here with this number three, right?
[00:01:44] It's the same thing, one bar long, three subdivisions equally spaced.
[00:01:49] And then we take another note here and say this one is subdivided into five equally spaced steps.
[00:01:57] So you can see it triggers at different points than here.
[00:02:01] And if you play the spec and repeat this, you basically have some kind of polyrhythm or it's called Polyrhythm.
[00:02:08] So the system length stays always the same.
[00:02:11] It's exactly one bar, but the subdivisions change.
[00:02:14] So this is how it looks like here inside of a note clip.
[00:02:17] So back to the Poly-Grid here, because someone asked me this on Instagram how you actually do polymeters inside the grid.
[00:02:27] So what are now polymeters?
[00:02:29] Polymeters are when the subdivisions stay the same.
[00:02:35] So let's say you have here 16 notes, right?
[00:02:39] To subdivide your one bar into 16 equally spaced steps.
[00:02:43] So it's 16 notes.
[00:02:45] But the length changes.
[00:02:48] So the length of this bar changes from one clip to the other.
[00:02:54] So to make sense of this, we duplicate this here and you want to change actually here the length.
[00:03:01] So your first initial idea would be, let's use an attenuate and say, I want to make this only a third note or a third of the initial length.
[00:03:14] So now you can see here the height is different than this one.
[00:03:21] It only goes to a third of the height of this one.
[00:03:25] So it's 0.3 and this is one.
[00:03:30] But you also can see that the steepness changes.
[00:03:34] And when the steepness or the slope changes of the ramp, you also change the playback speed.
[00:03:41] So let's say you have here a gates module.
[00:03:45] Let's actually use two.
[00:03:49] This one here and this one.
[00:03:52] So now we drive this here with these face signals.
[00:03:57] You can see here we have the initial playback speed, the real playback speed.
[00:04:03] And here you can see we only playback until this, until the third note here, right?
[00:04:09] Which is completely nice.
[00:04:11] But also the playback speed changes.
[00:04:13] It's not an eight note anymore.
[00:04:15] Let's go up to 16 notes here.
[00:04:18] 16 subdivisions.
[00:04:25] So the playback speed is different.
[00:04:28] It's not a 16 note anymore.
[00:04:30] So how can we change this?
[00:04:32] How can we change basically the playback length but don't change the playback speed?
[00:04:37] So attenuate is an interesting thought.
[00:04:41] So this was also my first initial idea, but it's not working that way.
[00:04:46] So what we need to do actually here is to duplicate this.
[00:04:50] And we need to use a face reset.
[00:04:54] So we need to reset the face at a certain point in the system.
[00:04:59] So what I do usually for that is, let's go in here.
[00:05:04] Let's use a trigger thing.
[00:05:06] Let's use the second one.
[00:05:08] And we need to go into here.
[00:05:12] Then we need a long delay because it's a feedback actually.
[00:05:18] Cut this short and then go back into the reset here, right?
[00:05:23] We want to reset the face and we want to reset the face at this point.
[00:05:27] So now you can see it loops basically between the beginning and this point in time.
[00:05:32] Or here.
[00:05:34] You can see also here the height changes, but also the steepness is the same.
[00:05:40] So it's still a 16 note in here, right?
[00:05:43] So we can now paint in a pattern, but this pattern loops at a different position.
[00:05:48] Or it's cut at a different position within the bar.
[00:05:52] I hope this makes sense.
[00:05:54] Actually, I have the feeling like I explain this completely complicated or more complicated,
[00:06:00] but this is how it works.
[00:06:02] So what we do with this kind of setup here with the reset thing is that we subdivide actually the length of the bar at a certain point in time.
[00:06:13] If you don't like to use here the gates for that, right?
[00:06:18] You can also exchange this and say we take here the math or logic.
[00:06:26] Is it logic?
[00:06:27] Yeah, this one.
[00:06:29] So we compare this here to a value.
[00:06:34] Let's say this one here.
[00:06:37] Now you can see you want to stop at 33% the length of this pattern.
[00:06:44] And then you take this value, basically loop it back and then reset here the face with this.
[00:06:52] So with this now, with this face output here, you can then loop at a different point in time.
[00:06:58] I hope this makes sense.
[00:06:59] So this is basically how you implement a Polymeters inside of the grid by just comparing here the face signal to a value and then use that to reset actually the initial face at a certain point in time.
[00:07:13] Again, this triggers module is a Polyrhythm device.
[00:07:18] It subdivides the same length, the same face into equally spaced steps.
[00:07:24] So it's basically a Polyrhythm device.
[00:07:26] And to do Polymeters, you need to use the reset module here.
[00:07:31] I think this is the best way.
[00:07:32] There are probably other ways to do this, but I use usually just a reset module here.
[00:07:37] And yeah, it's not that hard to set up actually.
[00:07:40] So this is my explanation for Polyrhythms and Polymeters inside of the grid.
[00:07:45] I hope you learned something.
[00:07:46] Leave me a like if you liked the video, subscribe to the channel.
[00:07:50] Thanks for watching and see you in the next video.
[00:07:52] And don't forget to ask questions, of course, in the comments down below.
[00:07:55] See you.
[00:07:56] Bye.
[00:07:56] Bye.