Last night Iranian kemence (spike fiddle) virtuoso Kayhan Kalhor and the Turkish baglama player Erdal Erzincan delivered an astonishing performance at the Old Town School of Folk Music, improvising on the loose themes of their recent album, The Wind. Though it’s not really fair to compare the two musicians–Erzincan’s instrument, a twangy, long-necked lute, is more limited than the kemence–but Kalhor was the more magnetic and dynamic participant. His ability to embroider simple melodic motifs and shadow his partner’s solos with ghostly harmonics was remarkable, as usual; whether he was plucking piquant little pizzicato licks or altering the tautness of his bow to change the tone of his lines, Kalhor’s technical mastery never upstaged his inventiveness. The performance consisted of one uninterrupted 65-minute suite, with various themes seamlessly connected with fluid bridges.