Around 1970, Gamble Huff Productions became Philadelphia International Records. When Eugene Dozier left the label, Sigler inherited his office. Sigler's songwriting break came when a tune he co-wrote with Phil Hurtt, "(You Are My) Sunshine", was released as a followup single to the O'Jays' million selling 'Back Stabbers'. Other Sigler/Hurtt tunes included on the 'Back Stabbers' album were "When The World Is At Peace" and "Who Am I". The O'Jays' followup album, 'Ship Ahoy', had Sigler's first solo written song, "You Got Your Hooks In Me", and the Sigler/Gamble tune "Don't You Call Me Brother".

In 1978, Sigler, bringing along Instant Funk, switched to Goldmind, a label started by MFSB guitarist Norman Harris and distributed by Salsoul Records. With his first release for the label, Sigler scored a Top Ten R&B single with "Let Me Party With You (Party, Party, Party)". The album of the same name was a smash in disco clubs. When Goldmind folded, all of its acts were transferred to Salsoul. About a year after its release and thanks to a Larry Levan remix, "I Got My Mind Made Up (You Can Get It Girl)", went on to be Instant Funk's breakthrough hit (number one R&B). Both that single and the 'Instant Funk' album went gold.