▁the ▁F ool " ▁followed , ▁as ▁did ▁their ▁second ▁album , ▁So ▁Much ▁Love . ▁This ▁success ▁land ed ▁them ▁a ▁came o ▁appearance ▁in ▁the ▁ 1 9 7 1 ▁film ▁The ▁French ▁Connection ▁( fil med ▁during ▁one ▁of ▁their ▁appearances ▁at ▁the ▁Cop ac ab ana ▁night club ▁in ▁New ▁York , ▁where ▁they ▁performed ▁a ▁cover ▁of ▁Jimmy ▁Web b ' s ▁" Every body ▁G ets ▁to ▁Go ▁to ▁the ▁Moon "), ▁as ▁well ▁as ▁an ▁eng agement ▁at ▁the ▁Riv iera ▁in ▁Las ▁Veg as ▁along ▁with ▁Engel bert ▁Hum per din ck . ▁ ▁In ▁ 1 9 7 3 , ▁when ▁their ▁contract ▁with ▁Rou lette ▁ended , ▁Bar rett ▁signed ▁them ▁to ▁Philadelphia ▁International ▁Records ▁under ▁Ken ny ▁Gam ble ▁and ▁Leon ▁H uff , ▁where ▁they ▁had ▁their ▁greatest ▁success es . ▁The ▁first ▁song ▁they ▁recorded ▁for ▁the ▁label ▁was ▁with ▁the ▁studio ▁band ▁M F SB , ▁titled ▁" TS OP ▁( The ▁Sound ▁of ▁Philadelphia )", ▁which ▁was ▁the ▁theme ▁song ▁for ▁Soul ▁Train . ▁In ▁October ▁ 1 9 7 3 , ▁the ▁group ▁also ▁made ▁an ▁appearance ▁on ▁the ▁American ▁television ▁sit com ▁San ford ▁and ▁Son ▁( season ▁ 3 , ▁episode ▁ 4 ), ▁singing ▁their ▁song ▁" I ▁Did n ' t ▁Know ". ▁ ▁Their ▁first ▁album ▁for ▁the ▁Philadelphia ▁International ▁label , ▁The ▁Three ▁D eg rees , ▁spawn ed ▁three ▁hits : ▁" Dir ty ▁Ol ' ▁Man " ▁( which