Mikey.666 wrote:but an amazing guitarist will not be as good on bass as a decent bassist.
hmmm... not so sure about that.....
I guess it comes down to your definition of "decent bassist" vs mine. I consider a "decent bassist" someone who can hold a groove and add that "little something" to the music other than simply the sound of his instrument. Some of the most notably and ridiculously simple basslines are courtesy of Michael Anthony (Van Halen) and Cliff Williams (AC/DC). We'd have to consider these two "decent bassists" for all they've contributed over the years but technically guitarists like Joe Satriani and Steve Vai can put them to shame on a bass.
People like Joe Satriani and Steve Vai and Eddie Van Halen are guitar virtuosos - masters of their instrument. In my books they're on par with bass virtuosos like Sheehan, Claypool, Geddy Lee, Steve Harris, and others. Satriani can't do what Claypool can do on a bass, and Harris can't do what Vai can do on a guitar...