Originally I wanted to post ""The Crime of the Century" from Ragtime, a terrific menage-a-trois-and-murder-themed song from one of my all-time favorite musicals. ("Oh! Oh!/Harry's a jealous man/Bang! Bang!/That was the end of Stan!") Alas, I could not find a video of the Broadway cast performing this number, though I did find this clip of a summer theatre group performing it so you can at least hear the song.*
Instead, I decided to post a different (but equally great) menage-a-trois-and-murder-themed song from another one of my favorite shows: ""We Both Reached for the Gun" from Chicago. A synopsis for those who (gasp!) are unfamiliar with the plot:
Chorus girl Roxie Hart (Renee Zellweger, here in the 2002 movie version) has murdered her lover and hired slick, handsome defense attorney Billy Flynn (Richard Gere) to represent her. At a press conference, Billy spins an alternate (and false) version of the murder in which Roxie acted in self-defense (because, you know, she and her ex "both reached for the gun"). This number is staged as a ventriloquist act in which Billy supplies the words coming from the mouth of his "dummy," Roxie. Naturally, the gullible press corps -- powerless before Billy's substantial charm -- gleefully laps up his story.
So please enjoy the clip, but be warned: you'll be singing this song for the rest of the day. Oh yes! Oh yes! Oh yes, oh yes! Oh yes! Oh yes! Oh yes, you will!
*To get a taste of just how amazing Ragtime is, watch the Broadway cast perform the show's opening number at the 1998 Tony Awards (at which it won Best Original Score) here.

