automatic beat matching crossfader

[aaronleese]

Hi all! First post on the forum.

I'm a computer programmer who dabbles in audio tech stuff. Have been working on a hack that uses echonest beat data to automatically beat match two pieced of music. This matches individual beats, not just the bpms. Thinking about also making it pitch shift automatically to place pieces of music in the same relative key automatically.

Any feedback welcome, thanks!

http://www.youtube.com/watch?v=FV0yN...eature=related

[nem0nic]

This is an interesting project to be sure, but it's fundamentally different than what a DJ typically does when mixing music.

The presumption you're making throughout this whole process is that DJs only care about the tempo of the music, and then only when the mix is actually happening. This is incorrect on both counts.

When a DJ mixes songs, he listens to not only tempo, but the phrasing as well (and key, but I'll leave that alone). Doing things like lining up phrases or drops is just as important as mixing the beat. So, a DJ needs to not only be able to mix the beat, they need to be able to hear the speed adjusted songs playing together in PFL in order to line up phrasing. Your method of mixing only effects the song's tempo during a mix, which kills the ability to hear the songs together in PFL before the mix, as well as the ability to line up phrases.

There's plenty of potential here, but you're not going to get anywhere by breaking a fundamental DJ use case. I think the best thing you could do is to work with an experienced DJ who could give you the insight into DJing your project currently lacks. You might also want to reach out to other open source DJ software projects, like Mixxx.

I'll keep an eye on this!

[Kupujte_Pytle]

this is really interesting. i can see this defo working for radio use.

[BradCee]

Intriguing concept... might try and map this in traktor for a giggle

[aaronleese]

Sure - I recognize this is not always desirable of course - but since it's easy enough to have it enabled/disabled I think it's could be a nice start on new and interesting ways to play with the beat of a song.

For example, rather than locking to either beat we could get both to warp to a master metronome, then speed them both up/slow down by large amounts. This could work with midi devices or sequences, or with the host program.

Lots to think about.

Also, since it doesn't rely on a comb filter calculation (the way most DJ programs determine bpm), it should be able to handle beats that are not steady, or change throughout a song, better than most programs (provided the echonest data is sound, of course).

Anyway - it's been a fun project for me. Thanks for all the feedback!

[spencer4hire]

Did you end up integrating this feature into the Livetronica?

[aaronleese]

Oh yeah.

Still tightening up the ways in which it uses the Echonest data, but this is how we do the tempo syncing. If you have loops running and drop a track on the turntables, then the track will try to grab beat info from echonest and then stretch appropriately.

There will be a control panel and all that before too long ..... so many little things to do

[spencer4hire]

I am going to play with your software tonight. I was wondering if you wanted a GUI designer to work with you?

I gotta say. The Livetronica GUI is ugly but the functionality is beautiful!

I think you have the right idea. You're going for a more minimal layout like Ableton or something close to Serato. Totally legit and spot on goal. But you have to remain consistent and apply emphasis on elements users interact with in a way that makes sense.

You mentioned this was open source but on the site I cannot find the Github link.