I'll add this bit. For me, the "definition" of the lyric also includes the vocal melody, the phrasing and rhythm of the words, and the "sound" of the words...all of which are integral to the music. I very rarely set poems to music. If something is going to change during the course of writing in service to the song, it's the lyric which usually gives way first...unless I've written a stellar line. Even then, I've written it in a way to be sung. Which is part of the music.

So music is boss, but the lyric is integral to the music. Which is boss.

BIAB 2021 Audiophile. Windows 10 64bit. Songwriter, lyricist, composer(?) loving all styles. Some pre-BIAB music from Farfetched Tangmo Band's first CD. https://alonetone.com/tangmo/playlists/close-to-the-ground