Rhythm Necklace

I have a thing for circular rhythm visualizations. So I was naturally pretty excited to learn that Meara O’Reilly and Sam Tarakajian were making an app inspired by the circular drum pattern analyses of Godfried Toussaint, who helped me understand mathematically why son clave is so awesome. The app is called Rhythm Necklace, and I got to beta test it for a few weeks before it came out. As you can see from the screencaps below, it is super futuristic.

The app is delightful by itself, but it really gets to be miraculous when you use it as a wireless MIDI controller for Ableton. I was expecting to use this thing as a way to sequence drums. Instead, its real value turns out to be that it’s a way to perform melodies in real time.

First, let’s talk about what a rhythm necklace even is. Take a look at these eight visualizations of son clave:

The top four are variations on standard Western music notation. The bottom four are more abstract representations telling you that the pattern is sixteen steps long, and that five of those sixteen steps have a drum hit on them. The fifth representation is called a time-unit box system, and it’ll be familiar to you if you’ve ever used a drum machine or software equivalent.

A rhythm necklace is a time-unit box system wrapped in a circle. Showing rhythms this way reveals some remarkable new information.

In conventional left-to-right notation, it’s difficult to see the symmetries of the son clave pattern, but on the circle, the tilted pentagon jumps right out you. Musical meter is a way to logically relate events that aren’t directly adjacent in time. The rhythm necklace makes metrical relationships more clear to the eye, and that helps make them clearer to the ear as well.

The Rhythm Necklace app is not the first circular beat sequencer out there, but it has some unique features. You can have up to four patterns running at the same time. Unlike every other app of its kind, Rhythm Necklace doesn’t require all of those patterns to be in the same time signature. Each pattern can have between two and thirty-four beat divisions. They’re all the same length; they just divide one bar of musical time into different-sized slices. If you run several odd-length necklaces at the same time, the results can be extraordinarily strange, the rhythmic equivalent of  harmonic dissonance.

You can generate patterns in some unusual ways too. If you tap one onset and then another without lifting your finger, the app will infer a symmetrical pattern and suggest it to you. If you select two onsets with three empty ones between them, for example, you can fill the rest of the circle with beats at that same interval automatically. You can also just tell the app how many onsets you want filled and how evenly spaced they should be. It’s especially interesting to change these parameters while the patterns are playing back, it makes for a super satisfying performance experience. You can take existing patterns and rotate, reflect, and invert them. These symmetry operations also sound great when you do them live during playback.

Rhythm Necklace has some limitations as a drum machine. You can only have four sounds going at a time, which restricts you to minimal boom-bap. You can change velocity globally, but you can’t vary it from one onset to another. If you’re trying to make a beat, the ability to continuously change the number of onsets with finger swipes is not too useful, because having your snare drum jumping around in the meter is more annoying than anything. The symmetry operations sound interesting, but in general, having your drum pattern changing all the time is not musically desirable (at least not for my purposes.) Maybe Meara and Sam recognized this from the outset, because the app doesn’t default to drum sounds, but rather to a melodic synth, and melody turns out to be where Rhythm Necklace really excels.

Sequencing melodies with Rhythm Necklace takes some getting used to. Each necklace plays one pitch, and you’re laying them out in time as if they’re percussion sounds. Logically, you could think of all melodic music that way, but it’s a new conceptual framework for sure. It’s worth making the effort, though. Given the extreme complexity of rhythm you can produce with the app, being limited to four pitches turns out to be a positive benefit. No matter how weird the beat gets, your ear can hold onto the simple and familiar pitch relationships. Alternatively, you can let the rhythms loop while bumping the pitches up and down. Being forced to keep the rhythm steady while the pitches change or vice versa is an excellent compositional restraint. It forces the music to have some coherence, and it keeps you from overwhelming the listener with too much information. I haven’t practiced this technique enough to have control over it, but just by stumbling around, I’ve had some very happy accidents.

Rhythm Necklace comes with a nice little sound library, and the interface for customizing the sound envelopes is especially elegant. However, to get the app’s fullest potential, you’ll want to use it as a MIDI controller for something more full-featured, which in my case is Ableton Live. Performing MIDI from a graphical interface on my phone that’s being sent wirelessly to my laptop is just about the most futuristic music experience I’ve ever had. Unfortunately, like many futuristic experiences, this one has a lot of bugs left to work out. Setting up MIDI over Wi-Fi is fiddly and unpredictable. The sync between the app’s MIDI clock and Ableton’s sometimes off by a wide margin. (Though having everything lag ahead of or behind the beat doesn’t necessarily sound bad; actually, it sounds pretty cool.) I haven’t tried a wired MIDI connection, but I imagine that would be more stable. Whatever, I’m sure this will all get ironed out in time.

I have some new features I’m hoping for in future versions. It would be nice to have a library of preset patterns, for example the Afro-Cuban necklaces that Toussaint talks about in his papers. It would be helpful to be able to see all four necklaces overlayed transparently. I could use some kind of numbering or shading so that I can find the backbeats more easily. Meanwhile, as it stands, Meara and Sam have taken a big stride toward the inevitable unification of math and music, and for that I am super grateful.

Update: I tried sending MIDI over my phone’s charging cable using midimux, and it works way better than wi-fi.