This show is the 50th anniversary of “Alice’s Restaurant Massacree.” Arlo’s father was known for wearing his politics on his sleeve. But while he has never shied away from politics, the message of Arlo’s “Alice’s Restaurant Massacree” are a little more subtle. In the 18-minute epic, Guthrie tells the true story of his arrest for littering, which was later used as grounds to bar him from serving during the Vietnam War. The story is somewhere between Kafka and the Three Stooges: pictures of the crime are presented before a judge, who enters the court with assistance of a guide dog. Guthrie only performs the song every 10 years, so catch it while you can.