For me it pretty much depends on what I'm building. I use music to get me in the mood of the subject.
So if I -let's say- build a Mercedes 540K, I listen to Max Raabe und das Palast Orchester, Marlene Dietrich, etc.
If I build an old Heller, I listen to Edith Piaf, Charles Trenet, Yves Montand, etc.
If I build a classic American, I listen to Benny Goodman, Glenn Miller, etc.
If I build a Fifties car, I listen to Dion & The Belmonts, Flash Cadillac, etc.
If I build a Pick Up or Truck, I listen to Alan Jackson, The Dillards, etc.
and so on...
Looking forward to building the London Bus, because I'll listen to Ashton Gardner & Dyke, some ancient Fleetwood Mac and the Honky Tinkers.