It is so sad. :( That's actually one of the two 52 issues I own in floppies (the other being when Renee puts on the mask). I went through the trades a couple months ago, and when I saw that in the commentary I decided I'm gonna have to make up some huge collage of where those lines are from when I get to that point in this series. I've been meaning to keep an eye out as I go through them, but the song's the only part I know off the top of my head.
The song is Danny Boy, an Irish funeral song. When they "killed" Vic in the first issue, Hatch told Shiva that if Vic rises singing Danny Boy, he'll give him anything he wants. When Vic confronted him in the second, he obliged.
As for the clown, I didn't cut anything between that panel and the one before it, you see it as it appears. Whether Denny put a random clown walk-by in the script or Denys was having a bit of fun, I couldn't say.