Back in the early 1990's, MTV Unplugged reintroduced American audiences to artists like Paul McCartney and Eric Clapton, and revealed a different dimension of Led Zeppelin and Nirvana. The show featured arena musicians presenting acoustic arrangements, deep cuts and influential cover material. Without the flashing lights and sonic support of the big stage, the songs themselves became the focal point. Thirty years later, this format provides a template for artists lik...