curtain raiser

from WordNet (r) 3.0 (2006)

curtain raiser
    n 1: any preliminary activity
    2: a short play presented before the main play

from Moby Thesaurus II by Grady Ward, 1.0

56 Moby Thesaurus words for "curtain raiser":
      Vorspiel, act, afterpiece, bit, chaser, coming out,
      concert overture, curtain, curtain call, debut, descant,
      divertimento, divertissement, dramatic overture, embarkation,
      embarkment, epilogue, exode, exodus, expository scene, finale,
      first appearance, floating, flotation, hoke act, inaugural address,
      inauguration, induction, initiation, installation, installment,
      interlude, intermezzo, intermission, introduction, launching,
      maiden speech, number, opener, operatic overture, overture,
      preliminary, prelude, prologue, routine, scene, shtick, sketch,
      skit, song and dance, stand-up comedy act, striptease, turn,
      unveiling, vamp, voluntary