The lyre had vertical strings of equal length (thereby differing from the harp) which were plucked, bowing being unknown in Greece. Pitch was regulated by the tension, and perhaps the thickness, of the strings. The strings of gut or sinew stretched upwards from a holder, over a bridge, to a cross-bar at the top of the instrument, which joined the two slender, curved, side pieces of horn or wood. At the cross-bar there were pegs for tuning. The sound-box at the bottom of the lyre was originally provided by the shell of a tortoise, often replaced by a similarly shaped wooden frame, with a piece of ox-hide stretched over its concave side. The player rested the instrument against his body as he played, plucking (and perhaps dampening) the strings with his left hand directly, and with his right hand plucking the strings with a device made for that purpose, the plectrum. The exact function of each hand is not clear.
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