Chicago, "25 or 6 to 4"
Green Day, "Brain Stew"
I think the similarities between these two songs vanishes after about 13 seconds, but for those first 13 seconds the songs swing in sweet sonic symbiotism. Chicago and Green Day, together at last. You wouldn't think Green Day would rip off jazz rock for a grunge punk riff, but maybe the two bands have more in common than I realized. You be the judge.