When Beatmakers Collaborate

Dear Rich: If a beatmaker gives me a song to write lyrics to, my understanding is that based on their intent to have words created for the beat we split the copyrights and publishing equally. Is my understanding correct? What happens when the beatmaker gives the same song to another person to write a rap or lyrics to it? Can they legally do that?
Your understanding of copyright is correct. Assuming you don't have a written agreement to the contrary, and assuming you both intend to merge your contributions into one song, you and the beatmaker are considered co-authors of a joint work and share in the copyright of the whole song equally. (Note: it's not always clear as to whether "beats" alone qualify for copyright protection.)
Multiple lyric versions. Songs can have more than one lyric -- for example "Love Me Tender/Aura Lee," or "Mr. Sandman/Mr. Santa." Although it may complicate ownership, the beatmaker can solicit different lyrics for the same instrumental tracks. These may be separate joint works, or derivatives of your joint work, depending on the timing of events (whose song is completed and recorded first) and the significance of your contribution (whether your contribution to the song is substantial). The most straightforward course of action is to document your arrangement with a co-writer agreement -- a simple document setting forth the intent of the parties, what the ownership percentages are, and signed by both parties. You can find more information about co-writer agreements at our LinkedIn Learning Course: Music Law: Copyrighting a Song.