On both sides of the stage improv-comedy's popularity has increased exponentially throughout the 1980s and '90s and into the new millennium. Presto An original song is created out of thin air. With nothing but a suggestion from the audience, daring young improvisers working without a net or a script create hilarious characters, sketches, and songs. Thrilled by the danger, the immediacy, and the virtuosity of improv-comedy, spectators laugh and cheer...