Mike Portnoy is one of the best drummers in the world. As a member of progressive band Dream Theater, he is known for his enormous talent displayed in intricate and elaborate rhythms. His technique and skill are a source of inspiration for many young drummers around the world.

After an entire life playing ofr the band he himslef helped create as a founding member, and after 12 studio recordings, Portnoy decided to leave the band, to the surprise of the rest of the band. The reasons can only be speculation but in one of his last interviews before leaving the band vimeo.com/14827294 he mentioned, very sincerely, how much he loved to play music wih other bands. Portnoy's musical influences range from the Beatles, The Who, Yes, Genesis, Pink Floyd, Metallica and a long list of very different bands.

Probably, Portnoy became bored of playing the same kind of formula with Dream Theater (hard, progressive and melodic) and got burn out of carrying on his shoulders being the heart and soul of the band in all possible aspects, compositionally and artistically. My guess is that Portnoy felt he needed to have fun palying with different groups that suited the versatility of his musical taste and probably found the super professional routine of Dream Theater was leading him to creative stagnation.