Musician AU!!! :D
Gabriel, Castiel, Michael and Lucifer. Also known as Heaven's Grace, a well known band that became popular after writing a world wide hit several years ago.
Sam and Dean. Fans of Heaven's Grace. Dean would write his own covers of their songs, and Sam was always encouraging him to do more with his musical talent.
Michael and Lucifer. They became fast friends after Luci found Michael as the drummer for their band, but it never progressed to anything more...
Gabriel, who loved the attention he got from fans. Yet he never even considered a serious relationship, instead settling for one night stands. He would always deny that he was lonely...
Castiel. The opposite of Gabriel, he hated being recognized outside of shows. He loved performing, he really did, he just wanted his private life to stay that way, private. No one really knew both sides to him, and that made it hard for him to get closer to people...
Dean loves pie and is oblivious. Castiel is blunt but doesn't understand human manners. Sam is a book worm scared of strange things. And Gabriel is...Gabriel.
They shouldn't work, they shouldn't be able to stand each other. But they do. Somehow they are meant to work together.
Maybe it was fate. Maybe it was by random chance. Or maybe it was while the angels had grace the hunters did as well, and their grace matched together; fusing into something new.