All of these sites allow for at least the initial creation of music for free as a tryout. After the creation of some music a small fee may be required to create additional music. For some sites, lyrics may be created based on your prompting. And some of the sites appear to be totally free.
AI Song Generator - Free
AI Music Generator (Media.io) - Free
Loudly - 25 songs per month for free
Tracksy.ai - 5 songs per month for free
Remusic - Music, songs, lyrics, etc.
AI Song Generator - You can create some rather nice compositions here