Hip-hop improv group takes freestyle riffs to new series

As a Tony-winning composer and writer, Lin-Manuel Miranda sees nothing of spending five years writing a show, or months on just a few lines of dialogue.

And then there's his other outlet: coming up with a rap routine - or maybe a skit, or poignant love song - within a couple of seconds, based on words tossed out by a crowd that's expecting brilliance.

The pressure of having to come up instantaneously with a rhymed riff on the subject of, say, Greek yogurt, or trigonometry, or customer-service operators, would probably cause heart palpitations in most of us, or at least hives.