Site for finding similar bands?

A while back, about a year ago I was really heavy into blues, especially electric texas blues. A friend told me of a site in which you could type the names of a few bands you liked or genres of music and it would recommend other bands you might enjoy. Now im really heavy into progressive rock, fusion, metal fusion, especially Joe Satriani. However id really like to find more artists as to increase my inpirational repitore. I realize its unlikely anyone will know the site I am refering to, however if they could turn me on to some guitarists or other instrumentalists of those 3 genres that can really shred but also play stunning melodies when it counts, then those opinions would be greatly appreciated.