It was an eminent stringed instrument of the singers (“aoidoi”) of Homeric epics. Homer himself characterized it as sweet and clear sounding.
It consisted of a small crescent-shaped soundbox elastically connected to two short straight arms enabling the imperceptible lateral motion thus creating a wave-like resonance. The strings started at the tailpiece, passed over the bridge (“magadion”) and tied with loops onto knots of leather strips which were wrapped round the crossbar. The careful rotation of each leather bulge permitted the tuning of the string.
The seated player held the phorminx in his left hand, slightly bent toward his thigh and with his right hand, he struck the three to seven (usually four) strings with the “plectrum”.