David is the absolute best. I've never had a better experience in a core class, or many other columbia class in general really. He's incredibly intelligent and insightful, especially for his age, and he made what could have been a really awful and boring survey course, a really fun and intensely interesting time. He gives you a lot of things to look at, listen to, watch, or read on the courseworks page, and it certainly helps to do them, but most of the time you can get all of the information from David in class the next day so it's not usually all that necessary. He is definitely very lenient with assignments and doesn't care whether you turn them in by hand or email, so long as he gets everything at some point or another. He specializes in minimalism and some other really great avant-garde kind of music, so he puts more weight and time into the 20th century section of the semester I think, which is totally fun and engaging (so, so much better I would guess than having a teacher who specializes in Renaissance madrigals or something). I also feel like the class was very centered around the philosophy and theory surrounding periods in music, composers, etc. so you read some pretty challenging articles (like some really crazy dense Adorno articles), but he does a great job of unpacking them with the class. He's open to anything you have to say, and even if you can tell when he doesn't agree with what you said or that what you said was wrong, he never shuts anyone down and if he doesn't understand your comment right away he'll ask you questions to try and figure it out instead of just moving on to someone else. Pretty much the nicest guy in the world, and really wants the class to be happy. Also, he makes the best witty comments at random all the time that never failed to make people laugh. He's fairly new to teaching so he gets kind of nervous and flustered sometimes, at least at the beginning of the semester, but its totally endearing and doesn't even remotely take away from what a great teacher he is. I can't say enough good things about David, it's a shame he's only a grad student because I wish I could take like five more classes with him. If you end up with him as your teacher, be happy, your core curriculum will be a hell of a lot more interesting because of it.