Apart from shawms with mouthed double reeds, there arose by the sixteenth century several forms of double-reed woodwinds played with the reed enclosed in a protective cap. These are known as reedcap shawms. On all reedcap instruments the player exercised little control over the reed with regard to timbre and dynamics, and, because it could not be overblown, the compass of these aerophones was restricted to that of a ninth unless enlarged by keys.
Of the seven sizes of regular shawms...