This program takes a melody and some chords as input and will automatically produce a four-part barbershop arrangement out of it. Elementary arranging rules will be respected.
For instance, say that you are asking AABA to arrange the melody and chords of "Down Our Way":
It might then produce the following arrangement, which is close but not identical to the Polecat arrangement:
Arguably, some voicing decisions that AABA made are not optimal, e.g. the bass should be on the low Bb on "Down". This is because not many rules are currently implemented regarding good voicing and voice leading decisions, and the weights of these rules are probably not ideal yet. If you would like to contribute your knowledge of arranging, or if you would like to contribute some of your own arrangements so we can let the computer learn rule weights through statistical analysis, please get in touch!
The easiest way to try out AABA is through the web demo, which will display the arrangement on a website and let you play it back.
If you want to compile AABA yourself, e.g. to run it on your local computer, you will need a recent version of Java.
Download the most recent release of AABA, or build it yourself from the current sources.
Then on your command line, run AABA as follows:
java -jar arranger-1.0.jar -o <outputfile.abc> <inputfile.abc>
Replace <inputfile.abc> by the file that contains your melody and chords in ABC notation (see below). Replace <outputfile.abc> by the name of the file to which you want the arrangement to be written. If you don't specify an output file name, arranged.abc will be used by default.
AABA uses text files in ABC format both for the input files (melody + chords) and for the output files (arrangement). You need to prepare the melody and chords in ABC format yourself, and you will need additional software for viewing and playing the generated arrangements.
As an example, have a look at the file down_our_way.abc in this repository. The notation of the chords is documented here.
There is quite a bit of software for editing, viewing, and playing ABC files. You need to be careful that your ABC software supports ABC version 2.1; older versions of ABC did not support multiple voices. I have been quite happy with EasyABC.
Check out the Github wiki and the Javadoc for more details.
A demo of AABA always runs on Heroku. To redeploy the current version of AABA to Heroku after making changes, run the following:
$ heroku login
$ ./gradlew build deployHeroku