Esto lo encontre vagando por YouTube, para que se rian un rato
John Petrucci Psycho Exercises 1
link: http://www.videos-star.com/watch.php?video=_J5_vqngHVc
John Petrucci Psycho Exercises 2
link:
John Petrucci Psycho Exercises 3
link: http://www.videos-star.com/watch.php?video=SrC_Wtm8v-0
John Petrucci Psycho Exercises 4
link: http://www.videos-star.com/watch.php?video=VOK8lYKlZ_o
John Petrucci Psycho Rig and Guitar Tech
link: http://www.videos-star.com/watch.php?video=ytIMN175keY
John Petrucci Psycho Exercises The Secret Tape
link: http://www.videos-star.com/watch.php?video=fkj19VarQx0