It may be a 50 Cent, hip-hop world at most American high schools today, but Pink Floyd, Led Zeppelin and Jethro Tull still rule at Thomas Jefferson High School for Science and Technology in Fairfax County. At least they do when the school's wildly popular Classic Rock Appreciation Club convenes its weekly meetings. The club's second year began with a bang and a wheeze yesterday when, speak of the devil, a very special musical guest came calling: Jethro Tull frontman Ian Anderson, 58, the flutist, singer and guitarist who has led the band through 21 studio albums and countless tours...