The upstream source is available from <URL: https://github.com/samaaron/sonic-pi >, and we are trying to add Debian build rules in <URL: https://github.com/georgesk/sonic-pi >. The default build system need some work before 'make install' will do anything sensible, and there are license issues with some of the files in the repository, but it should be possible to solve.
-- Happy hacking Petter Reinholdtsen