Lyric discussion by Omnius 

It does appear to be about sex, but I think it's more about the emotional aspect behind the sex.

"I know you don't want A love you can't sing The music was at the start"

My guess about this part is that the relationship isn't what it used to be, she used to sing to the music early on in the relationship but the music is gone now, hence why the song focuses more on the sex.

"The rhythm was all I needed to hear A woman can treat my heart"

To me this implies that the love they used to feel that is gone now was enough to at least partially heal the emotional pain in his heart (my understanding of Chet is that he suffers great emotional pain/depression. I know the feeling.)

This brings me to these lines:

"When I press an ear up to your breast I can hear the rhythm start It's hard to tell our beats apart

So I hope you're listening right now 'Cause I can barely hold my tongue The shit we do could warm the sun"

He knows she's also in pain (hard to tell our beats apart) and can barely hold his tongue from begging her to give that emotional connection another chance (the shit we do could warm the sun) possible completely heal each other.

Perhaps I'm over analysing it, maybe I'm projecting my own loneliness on the sad music I listen to, but that's my interpretation.

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