Originally Planet X began as a solo project for Derek Sherinian, but it later became a regular band for Sherinian, MacAlpine, and Donati. No permanent bass player has been chosen, and I don't think there are any immediate plans to add one. The music is well-done instrumental prog metal that should appeal to fans of other efforts from the members involved. While everything is well done, it seems at times that the music is written for vocals (yet having none), leaving me wanting something more. Perhaps I'm just too accustomed to instrumental bands that play a more technical metal style rather than a more traditional prog style.
In early 2004, MacAlpine left the band to pursue his solo career and tour with Steve Vai. T.J. Helmerich, who has worked with Donati in the past, was chosen to take his place. New material is being recorded for an unknown release date.