When his friend George Gershwin persuaded Vladimir Dukelsky to change his name to Vernon Duke, what the music world already knew became apparent to the public at large--the man had two musical personas--one as a composer, the other as a tunesmith. One wrote highbrow music, the other lowbrow. Yet the two sides complemented each other. Neither could function without the other. Born and classically trained in imperial Russia, Vladimir Dukelsky...