From MusicBrainz Wiki
- I used the "has additional guest other vocal performed by" AR but I feel it is wrong. Is there something like a "contains speech of another artist" AR? http://bugs.musicbrainz.org/ticket/3032 (asked by gioele on IRC, copied here by me --kuno).
- I would like some way to indicate that a track is a live performance of some other track in the DB, this was already suggested by someone else on the OtherVersionRelationshipType page. --kuno.
- I would like a "has book by" AR for musical theater. "Libretto" or "Lyrics" could be used, but neither is really correct for these. Wiki has a short (but decent) discussion/example of this: "In the case of musicals, the music, the lyrics, and the "book" (i.e., the spoken dialogue and the stage directions) may each have their own author. Thus, a musical such as Fiddler on the Roof has a composer (Jerry Bock), a lyricist (Sheldon Harnick), and the writer of the "book" (Joseph Stein)." http://en.wikipedia.org/wiki/Libretto -- BrianSchweitzer 05:10, 21 July 2007 (UTC)
- something to link multi-disc sets e.g. X "is the first disc in a set containing" Y, Z etc. This isn't ideal because a) only the first disc will point to all the discs in sets of 3 or more, b) you can have sets that overlap i.e. a disc belongs to more than one set, c) it's a bit of work for not much gain (though probably easily automatable in all cases but the ones where it counts e.g. two different sets with the same name but different component discs). Possibly one AR for two discs sets, and another for 3+ sets might make sense? Or, maybe like in Wikipedia you could link to previous and next discs in the series
- something to link Series of Releases (e.g. http://wiki.musicbrainz.org/Series). Similar issues multi-disc sets above i.e. link to next in sequence?, link to first?
- something to link compilations that consist of multiple entire albums (or an album and singles, or 2 or 3 E.P.s). Example: several Beach Boys 2-for-1 albums like Surfin' Safari / Surfin' USA
- a way to link to a person who whistles on a track using just their lips, as opposed to playing a [tin|slide|penny|referee's] whistle instrument like Alessandro Alessandroni on Titoli from A Fistfull of Dollars.