The correct spelling for the word pronounced "anvil choru" is actually "anvil chorus". The first word, "anvil" is pronounced /ˈænvəl/ and refers to a heavy iron block on which metals are shaped. The second word, "chorus" is pronounced /ˈkɔːrəs/ and refers to a group of singers who perform together. The Anvil Chorus is a famous musical piece from Verdi's opera Il trovatore, which features a repetitive chorus sung by a group of workers in a blacksmith's shop.