Few artists operated at the feverish pitch that Lee “Scratch” Perry did during his mid-’70s Black Ark studio days. Sound System Scratch raids the Black Ark vaults to unearth Perry’s rarest hidden treasures, from the drum-machine-heavy “Chim Cherie” to the echoing, cavernous “Dub Plate Pressure”. Familiar riddims from Perry’s oeuvre also manifest here in hallucinatory versions, such as “Roots Train Number Two”, a delirious, murky reimagining of Junior Murvin’s classic “Roots Train”.