Depends on the song tbh. Both definitely factor in but I think that the actual music takes a bit madami presence for me as I have listened to songs with absolute trash lyrics because it sounded good. On the other hand, I've liked songs for the lyrics and the story they tell.
The real gift songs are the ones with lovely lyrics and vocals to match; which is why Symphonic Metal is one of my paborito styles.
Zanny summed up things pretty well for me. It depends on the Song. There are times where the Melody makes the madami impact and others, where the Lyrics strike the biggest impression. If I had to choose one over the other, I'd say the actual Music for the most part ibingiay my experience. That aside, both together are ideal and make the best kind of Music !!!!