Centuries of trade and conflict between the Christian and Arab-Islamic worlds brought textiles, spices and bowed stringed instruments to Europe. No one knows precisely when the violin's middle-eastern ancestors first infiltrated the Mediterranean; though there does not appear to be one of them that the great Catalan viol player Jordi Savall has not been able to master.

Since founding the early music ensemble Hespèrion XX in 1974 (the group gained an additional numeral at the turn of the millennium), Savall has been one of the world's greatest exponents of the viol de gamba and its variants. For this opening concert of the 2014 York early music festival, he focused on a family of instruments including the cello-like rubab and its smaller cousin the lira, that were first depicted in 10th-century manuscripts.

The programme demonstrated how – until the expulsion of the Jews in the 15th century – the Iberian peninsula formed the nub of three great medieval cultures, Jewish, Islamic and Christian, in which Provençal troubadour song, Sephardic ceremonial music and Arabic maqam blended in a glorious musical melting pot. Presented as a continuous improvisation, the music was the product of mercurial virtuosity and scholarly guesswork, as very little secular instrumental music from the middle ages was written down. It also indicated how fluid the definition of early music has become, as some of the rhythmic figures and microtonal inflections might strike an Armenian traditional musician as entirely contemporary. As an encore, Savall prefaced a Kurdish dance from Syria with a prayer for peace in the region. Savall carries the title of official Unesco goodwill ambassador; and though his music may not be sufficient to quell the conflict, he can at least tend the flame of one of the world's oldest civilisations.

• Listen again on BBC iPlayer until 17 July. The York early music festival continues until 19 July.