Terry Kath is one of the best if not THE best guitarists of all time. He gets nowhere near the recognition that he deserves. Look up the stories about him and Jimi Hendrix. There are several documentaries out about Chicago. Check 'em out. I have always been a huge Chicago fan. Saw them several times in the 70s. They were so amazing before Peter Cetera got so full of himself. Annnnnd, if you want to see some really great covers, check out Leonid and Friends. Here's one of several they have done. Remember, Leonid, the bass player speaks not a word of English and he transcribed every one of the parts for these performances. While Street Player is not near one of my favorite Chicago songs, they absolutely NAIL it. Also check out the 'September' (Earth Wind and Fire) cover Enjoy!
Oh, and Ksenia isn't at all hard on the eyes. You'll know who she is.