My observation is that I first observed it used in that sense for hiphop music, exclusively, and assumed it comes from hiphop culture; I would guess it descends from "dropping the mic", but a quick peruse of UrbanDictionary reminds me there are umpteen other senses of "drop" in hiphop and other related music scenes (to kill someone, to pay a lot of money for something, the two old senses about drugs, a technical term from music, a technical term from dance, etc).
ETA: ohohoh! I forgot, and this makes even more sense: the idiomatic "drop some rhymes", meaning to perform improv/freestyle rap, I think pre-dates the sense of drop for whole albums/media recordings. That would be a natural and smooth transition from one to the other.
no subject
Date: 2018-06-09 06:15 pm (UTC)ETA: ohohoh! I forgot, and this makes even more sense: the idiomatic "drop some rhymes", meaning to perform improv/freestyle rap, I think pre-dates the sense of drop for whole albums/media recordings. That would be a natural and smooth transition from one to the other.
no subject
Date: 2018-06-09 10:50 pm (UTC)no subject
Date: 2018-06-10 11:10 am (UTC)