by William RuhlmannGuitar instrumentalist Marc Bonilla is to Robin Trower what Trower was to Jimi Hendrix, a slavish imitator who nevertheless goes off on tangents all his own. (Well, actually, some of Bonilla's tangents belong to Jeff Beck.) So, it's funny that on his second album, American Matador, Bonilla includes not one but two versions of "A Whiter Shade Of Pale," the initial hit by Procol Harum, Trower's old group. And what's the joke? Trower didn't join the band until shortly after that song was recorded!