As to execution, didn't care too much for the songs.
Well, it's not like the songs were original or anything. It was a very odd mixture, but then, these were older songs that Walter obviously grew up with. I don't think this was really meant as a "musical episode", it just had some bursts of a verse here and there, really.
Did they help? Probably not. But I did like Olivia's break out into "For Once In My Life" (I've always like the original slower version to the faster Stevie Wonder version)