The stays on period sackbuts are flat. The common wind instruments included the shawms, recorders, cornetts, sackbuts (trombones), krumhorns and flutes. The shawms, cornetti and sackbuts were used in loud consorts. The unusual combination of ancient instruments included rebecs, sackbuts, viols and crumhorns. Generally, loud consorts consisted of cornetti, sackbuts, shawms and the higher-pitched recorders and flutes. The brass group contains four or five trombones (sackbuts), three trumpets and two cornetts. Monteverdi ushers sackbuts into the first great opera, 'L'Orfeo' 1607. When pushed, sackbuts can easily make a loud and brassy sound.