Audio problem: When Daisy is at the bar (acting), she gives Walter "5 reasons men come to a bar." When she says "Three: They wanna see that they're missing," her lips are not in sync with the words. It's tricky to see because they used a shot with the camera behind her.
Continuity mistake: When Rube's talking to the graffiti artist, he's painting what looks like a blue cat. We cut away, hear a brief paint spray, then cut back. There's now far more painted than that spray could have achieved, and what was there already has changed as well.
Continuity mistake: When Daisy is in the diner with the other reapers talking about her acting job, the fruit in her hand changes from a red grape or cherry to a green grape.
Chosen answer: The Song is Callled "Boom Boom Ba" and is by the band Metisse. it plays at certain points during the series. Mainly when George is looking over Reggie or in Reaping Havoc where it plays whilst shes showing her scrapbook "Mysterious and Reassuring" which is what she thought Betty was.