In some cases, the artist who recorded the song may also own a share of the master rights. This is typically negotiated as part of the artist's recording contract. If the artist owns a share of the master rights, they can earn royalties from the sale of physical copies of the song and from licensing deals.
The value of master rights can vary depending on a number of factors, including the popularity of the song, the artist who recorded it, and the terms of the recording contract. Some master rights can sell for millions of dollars.