a soundtrack
A band that can't make it big, but they write that one song in a rom-com that everyone loves. No one remembers the band, but they'll never forget that song.
That song from the rom-com was amazing, but I have no idea who the band is.
I know that song from the movie, but I don't know who sings it.
That song was so good it should've been a hit, but the band just got lost in the shuffle.