While he hasn't released solo albums in the traditional sense, he has:
* Collaborated with other artists: He has featured on songs by artists like The Edge, Green Day, Luciano Pavarotti, Neil Diamond, Mavis Staples, and Kanye West.
* Contributed to soundtracks: He has contributed music to several soundtracks, including "The Secret Garden" and "Spider-Man 2".
* Released music under his own name: He has released a few solo songs, but these are more like one-off projects and don't constitute a full album.
So, while Bono's music is primarily associated with U2, he has also explored collaborations and other creative outlets throughout his career.