This post contains “Breaking Bad” spoilers:  http://m.us.wsj.com/articles/BL-SEB-77216

Last Sunday, in the penultimate episode of “Breaking Bad,” the familiar theme music for the Emmy-winning drama played in the show itself for the first time. The eerie slide guitar riff that defines the show’s opening sequence propelled the episode’s final moments, in which Walter White makes the fateful decision to leave his hiding place in New Hampshire and return to New Mexico.

Just music, no spoilers:  http://www.youtube.com/watch?feature=player_&v=61UEKToo3rw

John Jurgensen:  How did you create the Heisenberg hat theme? 

Dave Porter: The first sight of the black porkpie hat, I think, is at the end of season three, where Walt has to meet Gus Fring in the desert. There’s definitely a kernel of old Westerns in those moments, and I was trying reinterpret that a little. I lived and studied in Japan when I was younger, and I own a koto. It’s a great big zither. A stringed instrument. It has a twangy vibrato quality that isn’t so different from the resonator guitar that I used in the main theme.

JJ:  Did you play that signature guitar riff in the theme?

DP:  I play guitar, but very poorly. So the guitar was played by a friend who I’ve worked with for many years, Jim Heffernan, in his studio in Hoboken. The resonator guitar is big, made entirely out of metal, and very loud and brash. I wanted it to be bold and aggressive, as Walter would become.

Wow this theme is good.