(Can we add an example for this sense?)

First known usage is by Twitter user @TRACKDROPPA in 2009:^[1]

Voice so smooth its^[sic] like I’m singing in cursive..

cursive singing (uncountable)

1. (slang, humorous) The breathy, diphthongised pronunciation in which some Anglophone singers perform.

   Synonyms: singing in cursive, indie girl voice