Like many other subsequent acts the duo produced, which included Harold Melvin and the Blue Notes and The O'Jays, The Intruders had already developed a vocal sound that was both theirs and uniquely Philadelphian.

[7] Brown, Daughtry, Terry and Edwards had been recording and performing one-off singles together since 1961, blending Philly's street corner doo-wop tradition with black gospel fervor.

[8] Gamble and Huff's success with the Intruders helped convince Columbia Records to grant them the money to launch Philadelphia International.

[5] During the late 1970s and early 1980s, their music was popular on the West Coast among Latino, specifically Chicano, youth, as evidenced by their covers by the Hacienda Brothers and Tierra.

[2] According to Marc Taylor, in the book, A Touch of Classic Soul, in 1975, the other two original Intruders, Robert Edwards and Phil Terry, walked away from the industry after becoming Jehovah's Witnesses.

[14] This line-up is featured on the "My Music" DVD hosted by Patti LaBelle on PBS and tour with the Love Train: Sound of Philadelphia Concert series.