Typical stringed instruments of the early period include the harp, lute, vielle, and psaltery, while wind instruments included the flute family (including recorder), shawm (an early member of the oboe family), trumpet, and the bagpipes. Simple pipe organs existed, but were largely confined to churches, although there were portable varieties. Later in the period, early versions of keyboard instruments like the clavichord and harpsichord began to appear. Stringed instruments such as the viol had emerged by the 16th century, as had a wider variety of brass and reed instruments. Printing enabled the standardization of descriptions and specifications of instruments, as well as instruction in their use.