Thanks for the recommendations.
If you get the chance, also go to Düsseldorf, to Uerige, but also to Schlüssel, which I found even better than Uerige. And when you're there eat some Handkäse (https://en.wikipedia.org/wiki/Handk%C3%A4se) - you'll be thankful for the caraway seeds to mask the flavor
I have been to Düsseldorf many times and know all of the Altbier breweries in tha Altstadt. Last time we stopped at Schumacher's tap, Schlüssel, and Uerige. Uerige is my favorite, but that is my taste.
I lived in Hesse, so I know Handkäse mit Musik a few times. My German friends always said the music comes later.
Edit - we went to Köln (fixed the autocorrect this time), but concentrated on the museums and the Dom. Only have been to a few Kölsch breweries. Früh always had a big line at the door, so we passed.