Due to Alpha Muse being in open development, the ability to record and export songs is a work-in-progress. Thanks for your patience, and we hope to bring full functionality soon!
Alpha Muse 02a – does not feature song export
Alpha Muse 03a (released soon) – will feature in-game recording and sharing of songs. Exporting to wav/mp3 is not confirmed for this release, but is something we definitely want to include in future builds.