Petrucci Feedback trick

Hey guys, I was wondering how the hell John Petrucci does the feedback trick on the song As I Am. It's not a harmonic because he's not picking on fret 5 of the E or A string. He just does something with his whammy bar, and it all of a sudden does this exagerated whistling sound. Anyone know how he does that?

If your talking about the part right before the guitar solo, around the 5:00 mark, then that's artificial harmonics.....

Is that the part your talking about?

No, I'm talking about the beggining of the song at the 0:58 mark. He plays the note and does something with his whammy bar, and a feedback kind of thing comes out. He doesn't strike a harmonic either, the note just kinda "morphs" into this whistling sound. I don't know how else to explain it.

it might be a pinch harmonic which he then takes even higher into a whistling sound by pulling his whammy bar upwards, hence increasing the tension in the strings you need a floating trem to do this, i havent heard the song you are talking about but it sounds like a pinched harmonic to me, steve vai makes whistling sounds a lot i dont know if he uses this method to do it for definate but when watching dvd's of him live he appears to do so. Also zakk wylde uses a hell of a lot of pinched harmonics

if you dont know how to do a pinched harmonic, search this site im sure there will be a tutorial about it somewhere.

the best i can describe it is to let your thumb hang over the end of the pick very slightly so when you pick the note you thumb imediately touches the string causing the guitar to squeel (dont know how to spell squeel and i dont have spell checker at this moment in time to check). this is a pinch harmonic

Yes, I know how to perform a pitch harmonic. Anyways, thanks for your time, I figured out what it is. It's just a simple feedback he does. He moves his whammy slightly and if the volume is high enough, it will feedback, creating a strange howling whistling sound. You spelled squeel correctly. :)

Nvm, it's squeal. lol