Flutterby™! : Linux music and square dancing 2014-05-05 16:40:08.578091+00

Linux music and square dancing

2014-05-05 16:40:08.578091+00 by Dan Lyke 2 comments

Summary: A little bit on Linux audio, Mixxx DJ/mixing engine tool, Autotalent - autotune engine, JACK Rack effects virtual rack for the JACK low-latency audio API, with QjackCtl.

Full thing in the comments.

#Comment Re: made: 2014-05-05 16:40:16.690002+00 by: Dan Lyke [edit history]

This weekend, I got dragged down to a square dance caller's workshop in Sunnyvale organized by Rich Reel. It was a great experience, put me on the spot, showed me how much I don't yet know, and I'll be doing it again.

A square dance "tip" is about 10 minutes long, broken up into two parts: A "patter call", and a "singing call".

The patter call is done to a long rhythm loop, and is a sort of mental challenge. "Mainstream" square dancing has roughly 87 calls (depending on how you divide them), and is the lowest level you'll typically run into, at a big weekend convention, this'll be the room off to the side that has 2 or 3 squares going, with people moving a little slow. "Plus" adds another 31 calls, but starts to get more conceptual; you may learn a move done in a right-handed wave, but it's assumed that you'll be able to move that to a left-handed wave, there are common formations for various definitions, this is where a caller can say "okay, but try that from this other formation", or "do this complex move, but do ¾s of it, and do this other substitution in the middle".

The singing call is then something that flows, with sequences timed out to roughly 64 beats, cycling through partners in the square, with two or three interlude sequences, and in the longer sequences the caller will sing (old-time callers used to really work a sequence into lyrics, modern callers are assumed to mix up the sequences enough that this would be very challenging to do). Often the patter call

I'm struggling with how to structure my media delivery for the singing calls. Many callers use SqView because it has a tempo change slider and the ability to scroll a cue sheet, but I also want to mix up the music a bit; there's a ton of great modern karaoke tracks that I think can bring a new energy to square dance, but unlike music recorded specifically for square dancing, karaoke tracks might not fit that strict 8 measure sequence set, and don't necessarily have a melody line echoing the vocals.

Spurred on by a comment that Meuon made on the Chugalug mailing list, yesterday I installed Mixxx, and indeed it not only has the ability to munge tempo, it lets you loop by beats, so you can say "hey, I need an extra measure here", hit the 4 beat button, and bingo! And it's got 4 cue points that are easy to jump to, and that show up clearly in the timeline, so it's easy to say "the first rotation sequence starts *now*".

Because there's singing involved, I decided it'd be nice if I could clean up my voice a little bit. Discovered Autotalent, an autotune engine. On Ubuntu that's packaged for the JACK real-time audio API, and to control that I installed JACK Rack, and to patch the various components together in that, I installed QjackCtl.

So: Bring up Mixxx and JACK Rack, load the Autotalent module. Bring up QjackCtl and set outputs from both Mixxx and JACK Rack to the system, and set the system as the input to JACK Rack, and kaboom: Audio with autotuned vocals.

The one problem: Autotalent has a 43 millisecond latency. This is actually just enough to be really distracting, especially when singing to music that doesn't have that latency, and I'm not sure that adding the delay to the music and maybe playing the real-time into an ear bud and the delay out to the sound system (easy enough to do with this tool chain) would work.

Tonight I was cussing about installing Jack, because VLC was not working... (and I had installed the Jack plugin for VLC). Messed with it cussing for 10 minutes.