What are master rights?
"Master rights" derives from "master record", i.e. a master record with the original recording (tape), in other words a finished sound recording that comes out of the sound studio and is given to a pressroom to be reproduced. In order to publish a song you need master rights, which you own if you have produced and recorded a song. If your song has been produced by a producer you need the written approval of the producer to release and sell the song.