Knowing the different rights involved with creating and distributing your music is essential. "Master rights" is one of the most important rights to understand.
Master rights, in simple terms, mean that you own the sound recordings of your music. This includes both the original recordings of your songs and any copies that were made from them later. The person who is financially responsible for recording the music owns the master recording. In many cases, this is a record label. If you own the master recording, you have the right to distribute, sell, license, or use the recordings in any other way to exploit it for profit.
It's important to remember that who owns the master rights differs from who owns the underlying musical compositions, owned by the people who wrote the song and/or a music publisher.