The mandolinist Kenny Blackwell has had a trill a minute -- that's a mandolin joke -- on the West Coast bluegrass scene since the late '80s. Becoming part of the clique surrounding membership in groups such as the Desert Rose Band and the Laurel Canyon Ramblers, Blackwell also gets studio calls for various recording artists working in Los Angeles who might want a progressive bluegrass sound on a track or two. The fact that these types of sessions might not represent the most inspired side of his playing might be evident from the title of a brief Randy Newman track on which Bla...