The Rose Ensemble’s “Land of Three Faiths” program explores with audiences the rich musical, cultural, and linguistic exchanges and collaborations that took place among people of different faith traditions in medieval Spain. The result of years of intensive research and training, “Land of Three Faiths” is at once sacred, secular, folk, and classical. Featuring instruments and musical ideas that blur the lines between Arabic and European, this entertaining and enlightening program achieves a perfect balance of edgy improvisation, diverse vocal styles, and ancient traditions.