Didn't realize Dream Theater was in town tonight, but I did go to a local Guitar Center this afternoon for a clinic with John Petrucci. Pretty good time, he explained quite a bit of how he creates solos, and played a couple of DT songs on his 7-string. Was interesting to see how he uses that extra B string. Whenever possible, he likes to add a 9th to his chords. Sometimes that ends up being dropped an octave on the B string, giving a much darker tone. What I got out of it most was his demonstration of diminished chords and some of his picking techniques. Both of his new "Majesty guitars" he brought with him were 7-strings, pretty neat guitars with piezo bridge and USB-programmable analog pickups.