Rock and pop music produced a number of legendary singer/songwriters in the '60s and '70s -- artists who were celebrated as both performers and as tunesmiths. But Jimmy Webb was one of the very few who gained genuine fame as a songwriter that outstripped his recognition as a vocalist. Like Burt Bacharach (one of his key inspirations), Webb wrote some of the most iconic songs of the era, including "By the Time I Get to Phoenix," "Wichita Lineman," "Up, Up and Away," "MacArthur Park," and "Didn't We," and he often had a hand in the production and arrangements of their best-known...