Some information about the Viola:
The viola is a bowed string instrument. Music written for the viola differs from that of other instruments in that it primarily uses alto clef, which is otherwise rarely used. It is the middle voice of the violin family, between the violin and the cello. The viola's four strings are normally tuned in fifths. The term 'violist' is not used universally in English; 'viola player' is in common usage.