on the flip side, Wikipedia also specifies that a song includes vocals on their song page:
I think the main issue is that the word “Song” can mean very different things, depending on context. for a musicologist, it specifically refers to music with vocals. to the general public, it can refer to most any piece of music, vocal or not. this is probably why Wikipedia uses Song in their Instrumental article.
my two cents, I don’t think it’d be an issue to use the Song work type for instrumentals, as long as [no lyrics] is also set. I may be one of the few editors with this opinion tho…
long term, it might be good to have “Vocal Song” and “Instrumental Song” as types for popular music. even though they might not be correct from a musicologist’s standpoint, most editors are not musicologists. this would also allow us to better handle instrumentals with a few lyrics, I e. Tequila or Wipe Out, and also vocal songs without lyrics, such as The Great Gig in the Sky.
(oddly enough, all three examples are in the database as Songs, soo…)