Complex sentence: Harmonica Dan is the nome de plume of Dan Balcer, long-time clerk at the Philadelphia Record Exchange, whose woefully inadequate Discogs entry scarcely scratches the surface of his career.
Split into simpler sentences: Harmonica Dan is a nome de plume of Dan Balcer, a long-time clerk at the Philadelphia Record Exchange. His whose woefully inadequate Discogs entry scarcely scratches the surface of his career.