Part of the undeniable charm of "It’s Always Sunny in Philadelphia," even after 20 years on television, lies in its whimsical soundtrack — the satisfying irony of hearing rather pleasant tunes while ...

Rob McElhenney as Ronald 'Mac' McDonald, Kaitlin Olson as Deandra 'Sweet Dee' Reynolds, Charlie Day as Charlie Kelly, Danny DeVito as Frank Reynolds, and Glenn Howerton as Dennis Reynolds on 'It's ...