Song from an old Toy Story Commercial?

There is an old commercial for Toy Story 1 that has this old rock song in it. It has a recurring two-chord guitar riff with the first chord immediately followed by a second chord of a higher pitch (dunn-DUNN is the best way I could describe it). These two chords come right after or while the singer is saying "down"or "town" or "now" or something like that, maybe "bringing me down" or "holding me down"? Whatever he says he stays on it for a while (like "doooowwwwn"). Also I remember that at the end of the commercial the narrator said "the fun begins October 29th (release date for Toy Story VHS)".