The lyre or lyra is a stringed instrument with a distinctive shape. The history of the lyre is lost in the mists of time. It existed during the Sumerian civilisation and was played by the ancient Egyptians. However, the instrument is most frequently associated with ancient Greece. In Greek antiquity, the lyra was mainly an instrument for the amateur player. According to tradition, the first lyre was made by the god Hermes, the messenger of the gods, from a tortoise shell, to which a framework of sticks was affixed. In the first millennium of western European civilization, the lyre is depicted in illuminated manuscripts. During this time, the lyre was plucked with a plectrum instead of being strummed with the hand. The lyre is quite similar in appearance to a small harp but has certain basic differences.

The classic lyre has a hollow body, called the sound chest. Two raised arms extend from this soundchest. These are hollow and curved both outward and forward. Toward the top they are connected by a crossbar or yoke near the top. The bridge is made up of an additional crossbar which is fixed to the soundchest. It is this bridge which transmits the vibrations of the string. The strings were made of gut. They were stretched between the yoke and bridge, or to a tailpiece below the bridge. The lyre could be tuned in two ways. One way was by fastening the strings to pegs which might be turned. The other way of tuning the lyre was by means of changing the place of the string on the crossbar. Both methods were in simultaneous use.

It is known that the lyre occurred in various forms and could be played in any number of ways. It is generally held to be a part of the zither family. The musicologists rely on the depictions encountered in contemporary accounts, and these are not always reliable. It is therefore no wonder that no complete treatise exists that deals with stringed instruments of the Middle Ages. The number of strings ranges from three to ten and they are usually plucked with the fingers or with the nails, or they can be strummed. Sometimes the left hand is used to hold down a string.

The medieval European lyre is much more simply constructed, consisting of a shelf that serves as a sounding board, from which a section of wood is cut. The transition from playing the instrument by plucking to bowing took place around the tenth century. Nowadays, modern plucked lyres can only be found in Africa and some parts of Siberia. Some bowed lyres are still in use.

There are different forms of the lyre found the world over. Crwth is a bowed lyre that was especially popular in Wales. Its Irish counterpart is called the `emit.` It has four stopped strings that run over a central fingerboard. The construction of the bridge is unusual, in that it consists of two parts, one of which rests on the top of the sound box, while the other acts as a sort of support and runs through a small sound hole to the bottom of the sound box, to amplify the sounds. There are two bass strings. In Finland and Estonia, a folk instrument, the kantele harp, shares a number of features with a comparable instrument from the valley of the Siberian River Ob. In this form of harp, there is an opening cut from a rough wooden plank. The instrument has three or four strings made of horsehair stretched over it, which are then bowed or plucked with the hand.