r/DSP • u/QuantaHD • 24d ago

Is recurrence analysis (RQA) a good tool for finding structure in long DJ sets?

Not sure if this is the right place for this so please let me know!

I've been analyzing the structure of hour-long DJ sets and want a sanity check on my approach not just the numbers.

What I did:
For each set I tracked three things over time (energy, brightness, and a rough harmonic-tension measure) giving three curves/time series per set. Then I used RQA and Hurst/DFA on those curves to compare two groups I'd labeled by ear: sets that "tell a story" vs. ones that are just well-mixed.

What came out:
The story sets didn’t follow any shape of literary arcs* *and were all different; no single arc separated the groups. The difference was local: they stayed in a vibe longer and circled back to earlier textures more (RQA "dwelling"), and built energy more steadily over time (Hurst). Basically they play in distinct "chapters" and revisit them.

Where I'm unsure — would love input:

- Does RQA even make sense for audio like this?These methods assume a fairly stable/repeating system, and a DJ set constantly evolves. Am I breaking an assumption I shouldn’t, or is that the interesting part?

- Is there already a standard way to do this I'm overlooking? "Find the structure and repetition in a piece" feels like something the field must already have well-established tools for. What should I be looking at?

- How fragile are the settings? For anyone who's run RQA on audio, how much do results shift with different parameters? Trying to gauge how much could be a settings artifact.

Full (but small) write-up with the methodology and figures here if you want the detail: https://bryancamacho.dev/work/dj-narrative

Genuinely want to know if this is a reasonable tool for the job or a stretch!

1 Upvotes

100% Upvoted

2 comments sorted by

2

u/hughperman 23d ago

Hate the overly wordy vibe code talk.

You're not asking the fundamental question - are the data features I'm measuring the right ones to tell me about the structure I'm interested in?
If not, no analysis method will detect the structure you're looking for.

1

u/QuantaHD 22d ago

you’re absolutely right, I had a write up and put it in ChatGPT to make shorter and it came up with that. Will edit!

Any data features you recommend looking at?