Three teenagers have pleaded guilty in the beating death of Seattle's "Tuba Man," but none will spend more than 72 weeks in juvenile detention for their crimes. ... Ed McMichael, 53, a quirky character known for playing everything from Black Sabbath to Bread on his tuba while outside Seattle sporting events, was pummeled by a group of teens after midnight on Oct. 25 last year. ... The Garfield student admitted, Satterberg said, to delivering one unprovoked punch to McMichael's head, knocking down the Tuba Man. Others in the mob kicked McMichael as he lay in the fetal position and rifled...