hold on a sec. modes, as we are familiar with them, ARE a medieval concept. that they have (mistranslated) greek names is of little importance. but "mode" as an overarching musical concept is not attributable to any one culture or time. both ancient greek and medieval european music were modal in nature, but otherwise the two systems have few similarities. the modes of medieval music represent only one of many sets recognized by the ancient greeks. uprigbassjunkie - i think you are mixing up periods. medieval music was primarily vocal and the secular stuff might have used psaltery and harp. but no keyboards! the problems with enharmonic notes on gambas and keyboards started in the renaissance and were due to the departure from pythagoreanism. so equal temperament (as a pretty good pythagorean approximation) would sound ok for medieval music, but not so good for renaisance/baroque music.