From Longman Business Dictionary
royaltyroy·al·ty /ˈrɔɪəlti/ noun (plural royalties) [countableC]COMMERCELAW1a payment made to someone who owns a COPYRIGHT or a PATENT (=legal right to be the only producer or seller of something), for example an inventor or the writer of a book. The amount depends on the number of products or copies of the work which are soldThe writer gets a 10% royalty on each copy of his book.
Royalties from the song will go to charity.