The Mix Machine

The Mix Machine is a collection of scripts to automatically make DJ mixes.

Given a collection of mp3's The Mix Machine will beatmatch or crossfade tracks, and spit out a single mp3 file with a continuous mix. At the heart of The Mix Machine is a python script (mix_machine.py) that utilizes the EchoNest remix package and API to do audio analysis. Parallel processing is used wherever possible to speed things up.

The Mix Machine can do the following:

1. Convert your music files to a common mp3 format (remix will barf on some music files)
2. Upload your files to EchoNest
3. Order the music files in terms of tempo
4. Mix the files, beatmatching where appropriate, or fading when the tempos are off

Requirements

1. Set your EchoNest API key export ECHO_NEST_API_KEY="your api key"
2. The remix python package pip install remix

Usage

1. Put your mp3's in a directory
2. Edit the variables at the top mix_machine.sh, including your Echonest API Key
3. ./mix_machine.sh

Output quality

By default remix will output 120k mp3's, and to my knowledge there is not a way to change this. I had to hack the remix source to allow for 320k files.

mix_machine.py

mix_machine.py is a standalone script that does most of the work of putting together the mix. It can be used separately from The Mix Machine shell scripts.

Usage: mix_machine.py [options] <list of mp3s>

Options:
  -h, --help            show this help message and exit
  -a APIKEY, --apikey=APIKEY
                        EchoNest API key (required)
  -x CROSSFADE, --crossfade=CROSSFADE
                         fade between songs default=10
  -f, --fadeonly        beatmatch and fade only, don't temposhift and
                        beatmatch tracks
  -o, --order           automatically order tracks
  -e, --equalize        automatically adjust volumes
  -v, --verbose         show results on screen
  -m, --multiprocessing
                        Use the multiprocessing module to run taskes in
                        parallel.

Disclaimer

Does The Mix Machine make human DJs obsolete? Heck no!

The Mix Machine can only do so much with what it has, if two songs don't match up well, the trasition will be weird, no matter what. It takes a lot of thought to put together songs that will flow well, and no amout of software will replace a good DJ.

History

The Mix Machine is heavily based on the remix example capsule.py. Originally The Mix Machine was just a hacked version of that script. capsule.py was basically inteded to make power hour mixes, and so had some subtle differences from the application of making a DJ mix, where we want to include as much of the song as possible. It ended up being easier to re-write most of the code to be sure everything was working correctly.