Historians have settled on 1498 as the founding date of the Vienna Hofmusikkapelle (court orchestra) and, consequently, the Vienna Boys Choir. Until 1918, the choir sang exclusively for the imperial court, at mass, private concerts and functions and on state occasions. Today, about 100 choristers between ages 10 and 14 are divided into four touring choirs that give some 300 concerts and performances each year before nearly half a million people. The choir?s repertoire includes everything from medieval to contemporary music. Together with members of the Vienna Philharmonic Orchestra and the Vienna State Opera Chorus, the Vienna Boys Choir maintains the tradition of the imperial musicians providing music for the Sunday Mass in Vienna's Imperial Chapel, as the choir has done since 1498.