Occasionally, a song contains a two-part guitar solo with both rhythm and lead guitar taking solos (e.g., "Master of Puppets" by Metallica), or dual solos with both lead and rhythm playing complementary solos—such as with Twisted Sister’s "30", Iron Maiden's "Hallowed Be Thy Name", "The Trooper" or Megadeth's "Mechanix". Some rock bands use harmonized dual lead guitar solos as part of their signature sound, such as Wishbone Ash. This was first popularized by the Allman Brothers Band in their album "At Fillmore East".