London: Jubilee Line at Speed The Tube is an underground Trumpet or Trombone, existential frictive metallic rim; steel wheel on rail, wail of tempered line, roar of its own metallic applause pressing through mind-the-doors: a rush of snare drum   and kettle drum with stick on rim staccato, a grand chorus of massive voice. The train is its own movable valve pushing the air, an exhalation from the underground an exhilaration for passengers; a left-field satchmo.     Clint Eastwood Elementary USA In every class room Boom Boom Boom. Ivan Head     On being asked to choose my gender…