Sometimes, one band writes a song, or publishes an album, which has the same name as a different band. For example, last night lark_ascending played me some music by ‘Van Canto’, including a song called ‘The Mission’. And Leonard Cohen had a song called ‘Sisters of Mercy’.

It occurred to me last night to wonder how common this is. In particular, my most immediate thought was this: if one were to define a directed graph on bands with an edge from one band to another iff the former had a song or album named the same as the latter, would the graph be cyclic? That is, does there exist a band called A with a song/album called B, and a band B in turn with a song or album called C, and … eventually some band X with a song or album called A? My own knowledge of music is less than encyclopedic, but I wonder if any music-trivia buffs among my readers might enjoy having a try.

(Standard conventions for directed graphs apply: it's cheating for a band to link directly to itself, but two bands linking to one another are a valid cycle. Also, I'm prepared to be a little forgiving on the matter of whether or not band, song or album names have a leading ‘The’. Finally, I don't demand that the name matches be coincidental: if the song name directly inspired the band name or vice versa, as in the second example above, that doesn't disqualify the link.)