There was a rousing chorus segment with trumpet-sounding horns and drums. Having not been born in the 70s, I heard those notes of the song in the 90s and early 2000s. If I remember, the lyrics sounded political and the singer was a little baritone and might have been African-American. Maybe but maybe not, "changing" was repeated in the lyrics.

A couple songs that sound like the one I can't remember is "Hard Times" by Baby Huey, and 'For The Love Of Money' by the O'Jays.