The companion piece to The Sound of Philadelphia hits collection is an hour-long trawl through the deepest recesses of the Gamble/Huff vaults. As the title suggests, these songs never dented the charts and only deep soul enthusiasts even recognize most of the artists. But for those seeking to peel back the layer of fluff that surrounds the label's most defining work, these 16 diverse rarities hit the mark. The music is generally tougher, rawer and more blues-based with singers such as the gravelly Bobby Bennett and People's Choice bringing a sturdy, testifying style not typically associated with PIR recordings. Ruby's Surprise Party checks in with a funky one-off that sounds more Memphis Stax gruff than Philly International smooth and Bunny Sigler out-Shafts Isaac Hayes on a truly mind-bending, psychedelic "Theme for Five Fingers of Death" that is probably in Quentin Tarantino's personal collection of soul oddities. 5 stars.