"Harry, I'm going to let you in on a little secret. Every day, once a day, give yourself a present. Don't plan it, don't wait for it, just let it happen. Could be a new shirt at the men's store, a catnap in your office chair, or two cups of good, hot, black coffee. Like this."  -Dale Cooper

Leland Palmer/Bob doing "Behind Blue Eyes." It just... fits.

It would definitely be cooler with original songs and lyrics created by Lynch and Badalamenti.

But I could see a whole dance number of Ben Horne singing "Money" by Pink Floyd with an onlooking Jerry Horne in Ben's office.

Possibly even Dell Mibbler performing a Slayer cover song.

"Harry, I'm going to let you in on a little secret. Every day, once a day, give yourself a present. Don't plan it, don't wait for it, just let it happen. Could be a new shirt at the men's store, a catnap in your office chair, or two cups of good, hot, black coffee. Like this."  -Dale Cooper

having never seen the buffy series, im going to go with a safe one here
BOB singing "light my fire" by the doors in just about any setting, including the black lodge.
sorry, im home sick from work today, and thats the first thing that popped in my foggy brain.

did the buffy episode use original music, or covers like we are suggesting here?

The working men (loggers, mill workers) of Twin Peaks after a bite to eat at the Double R sing "Cherry Pie" by Warrant as Norma and Shelly dance suggestively on the counter top.

Also - John Justice Wheeler singing How Deep Is Your Love to Audrey while getting down with his tucked-in sweater bad self.

EDIT - The Buffy episode was all original music and even spawned a soundtrack.  So you can create your own songs about donuts or giants or drape runners or whatever.

"Harry, I'm going to let you in on a little secret. Every day, once a day, give yourself a present. Don't plan it, don't wait for it, just let it happen. Could be a new shirt at the men's store, a catnap in your office chair, or two cups of good, hot, black coffee. Like this."  -Dale Cooper