The groundbreaking work of this British psychedelic-blues supergroup deserves more thorough study, but this 20-song compilation provides a useful overview for newcomers. Eric Clapton, Jack Bruce, and Ginger Baker--virtuosos all--expanded the parameters of rock by incorporating a jazz sensibility into their distorted blues jams. This compilation mixes their odd original hits with a number of souped-up blues covers. The live version of Robert Johnson's "Crossroads" remains one of the greatest blues workouts a rock band has ever produced. Since Cream released only four albums, this set includesv most of the highlights, and it illustrates how Cream cast the seeds of heavy metal. -- Marc Greilsamer