Trans-diegetic music: Swiss Army Man

This clip from Swiss Army Man is an interesting example of music transcending the film's diegesis. The song is intentionally titled "Montage", and is sung by Paul Dano and Daniel Radcliffe, yet there's not much singing depicted in the clip besides Radcliffe occasionally repeating "pop popcorn". The lyrics seem to narrate everything they do, from killing a raccoon to starting a fire. Imagination is a key element in Swiss Army Man's narrative (after all, Radcliffe plays a dead body that happens to function as a magical omnipotent tool), and "Montage" works as a bridge between music inside and outside the diegesis.