What goes a long way in making it work is that the authors have managed to craft a plot that almost reasonably connects the pre-existing songs (there are new ones, too) into something resembling an integrated score. Buffett wrote a song about a volcano? Okay, make a character an environment scientist working with volcanic soil. A song about cheeseburgers? Okay, have a character struggling to stay on a diet. A song about being comforted by things like grapefruit and Juicy Fruit? Okay, that's the 'Whistle a Happy Tune' moment. 'Why Don't We Get Drunk (And Screw)'? There's the audience participation number! Wait, the main character needs a philosophy of life song. 'It's Five O'Clock Somewhere'? Perfect!