I don’t usually hear that phrase in the music biz…I usually hear it in reference to a script or comedy bit.
Script writers and joke writers get their best draft together and then bring it to their writer buddies to tinker with it. Punch it up. Make it shimmer. Add some sizzle. Not big strokes, meaningful little ones.
The people punching it up may not get credit for the subtle re-writes but it doesn’t matter. Being trusted to make the thing better is what matters.
We need this more in songwriting and production. Punch up the song…two or three little things that might make a big difference.