obvious examples: when a singer takes over their band towards the end of the band's lifespan, and it's clearly their first solo album (Terror Twilight)
or when a band "reforms" but really it's just the singer doing a solo album under the name (the last Hole album)
or conversely when a guy releases a solo album after breaking up the band, but essentially it has the same personnel as the band's last albums (Mark Hollis)
or when a band reforms under a different name (eg rites of spring/happy go licky or cap'n jazz/owls)
or in rap/other music with lots of collectives (wu tang)
or in jazz (making a v. spurious argument that kind of blue is a john coltrane album).
~~this thread is better than most threads.~~