Songwriters-producers Kenny Gamble, Leon Huff, and Thom Bell became legends of Philly Soul in the 1970s, gaining the nickname “The Mighty Three.”

Together, the trio have produced an output of approximately 3,500 songs. The producers are also the founders of Philadelphia International Records, a record label celebrating its 50th anniversary this year.

Now, a new documentary will chronicle the development of the Philly Soul sound and these three prolific contributors.

Titled The Sound of Philadelphia, the upcoming documentary will focus on the contributions of the three Philadelphia soul legends, who produced music with the Jacksons, The Three Degrees, Elton John, The Temptations, and the Supremes among many others.

The documentary is being produced by Warner Music in collaboration with Imagine Documentaries and Jigsaw Productions.

During the 1970s, the influence of Philly soul reverberated throughout the city, region, and nation. 

One hit — ‘TSOP (The Sound of Philadelphia)’ from MFSB, with vocals by The Three Degrees — would become the theme song for Soul Train, and the source behind the documentary's title.

Of course, Gamble, Huff, and Bell themselves worked with MFSB.

MFSB (“Mother Father Sister Brother”) was a notable collective of Philadelphia musicians, pulling from a pool of over 30. The group was based out of Philadelphia’s defunct Sigma Sound Studios.

The Sound of Philadelphia will showcase exclusive and rare footage of Gamble, Huff, and Bell. The trio recently had the chance to share their excitement over the project:

“After six decades, we are incredibly proud to finally share our life stories with the world and showcase all the hard work that has gone into creating this great music,” shared Gamble, Huff, and Bell in a statement.

As Gamble, Huff, and Bell’s legendary record label celebrates its 50th year, The Sound of Philadelphia will channel its own celebrations of Philly Soul’s history through the documentary’s storytelling.

“Our longtime fans and new fans will get a unique look into the creation of the Sound of Philadelphia,” continued the trio, “with the themes of empowerment and love, to ‘people all over the world’ as we’ve always had a ‘Message in our Music!!!’”

In their closing regards, Gamble, Huff, and Bell reference a classic tune from Philadelphia International Records affiliate, The O’Jays.

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The Sound of Philadelphia does not yet have a release date.