Yes! I caught the second half of this movie on tv the other night—the scene you described where the dad and his buddy are freestyling is what drew me in. Also this stirring rendition of "Knockin' on Heaven's Door"
Aside from the song itself (and the dancing! and the terrible lip dubbing!), how about that performance from Ruben Studdard? “Unbelievable. He’s in the finals!”