David Bowie was as agile a shape-shifter as pop music has known; for more than 50 years, he toyed with innumerable guises. “The Laughing Gnome”, from 1967, subtly tweaks the era's psychedelic folk rock; “Dancing In the Street”, a 1985 duet with Mick Jagger, puts a tough, joyful spin on the Motown classic; and on 1997's “Little Wonder”, he dives into drum 'n' bass breakbeats with unexpected gusto.