Possibly Jimmy Williams’ finest hour, the lead single from McFadden & Whitehead’s self-titled 1979 debut, ‘Ain’t No Stoppin’ Us Now’ proved to be a huge hit for the duo, achieving double platinum status, appearing on the soundtrack to Boogie Nights and serving as a celebratory anthem for countless sports teams.

McFadden & Whitehead had already established a successful songwriting career prior to stepping into the spotlight, writing and producing for artists including The O’Jays and The Jackson 5. In fact, Philadelphia International Records owner Kenny Gamble tried to convince the pair to give ‘Ain’t No Stoppin’ Us Now’ to The O’Jays, for whom they had written ‘Back Stabbers’, rather than attempt to become performing artists in their own right.

The sublime bassline on ‘Ain’t No Stoppin’ Us Now’ was played by Philadelphia International Records house bassist Jimmy Williams, whose credits also include The Trammps, The O’Jays, Gloria Gaynor and Teddy Pendergrass.

Jimmy’s part immediately begins with a hook: a 2-bar phrase that alternates between a descending scale figure and driving, quarter-note roots to outline the harmony. The slash chords in this section, which reappears later as the bridge between verse and chorus, are built using a triad over a bass note a tone higher (Gb major with an Ab bass and Eb major with an F bass), which result in a suspended chord sound. This is a common songwriting trick to create tension without using dominant chords, which can often sound too tense in a commercial pop context.

The main groove, which has become one of the song’s definitive musical elements, is another 2-bar phrase, constructed using the ‘question & answer’ formula upon which so many classic basslines are built (think about ‘Another One Bites The Dust’ and ‘Good Times’). The Bb minor phrase is the ‘question’, while bar 2 is the ‘answer’. Note the melodic slide into the 9th (C), which provides contrast to the shorter note lengths.