
For those of you unfamiliar with the group, they are basically a improve group in Chicago that puts on very funny shows. There are a couple of different versions of the group, but it got its start in Chicago back in the 60s. Second City is also known as a starting point for comedians and actors, as some people in the troupe eventually go on to bigger things, like (often) becoming a cast member on Saturday Night Live. There is also a very impressive list of Alumni including stars like Alan Alda, Harold Ramis, John Belushi, Tina Fey, Keegan-Michael Key, etc.
Here's a link to the list if you want to learn more: Link
Going back to the post, I have seen two shows of Second City when I was in Chicago and they are brilliant. Like I mentioned earlier they are able to transition between both high and low comedy in a very impressive way. One moment they will be doing some slapstick and the next thing you know, they're talking about a political person or making references to homosexuality. I remember during one of their shows there was an ongoing thing with someone giving CPR to someone in a very forceful fashion (if it sounds weird, that's the point) which is low humor, seeing someone in pain. It then transitioned to two gays having dinner trying to get to know one another on a date and the things they try to relate to is high comedy, requiring some good thinking on the audience's end. What's also really impressive is that almost the entire routine is improve. There might a scripted scene or two, but for the majority, it's improve so the fact that they can do this is really something to see.
I really can't say much about Second City as you need to see it in order to understand why it is funny. The first act will seem really random as it will be nothing but random skits one after another but that's the point. Really, just go and see it. I guarantee that you won't be disappointed as they bombard you with their high and low comedy and improve.