A single-reed instrument is a woodwind instrument that uses only one reed to produce sound. The very earliest single-reed instruments were documented in ancient Egypt, as well as the Middle East, Greece, and the Roman Empire. The earliest types of single-reed instruments used idioglottal reeds, where the vibrating reed is a tongue cut and shaped on the tube of cane. Much later, single-reed instruments started using heteroglottal reeds, where a reed is cut and separated from the tube of cane and attached to a mouthpiece of some sort. By contrast, in a double reed instrument (such as the oboe and bassoon), there is no mouthpiece; the two parts of the reed vibrate against one another. Reeds are traditionally made of cane and produce sound when air is blown across or through them.