By 1975 the group had built up a repertoire of 120 works, including the complete Beethoven, Schubert, Cherubini and Bartók quartets, and works by Haydn, Mozart, Brahms, Hugo Wolf, Pfitzner, Verdi, Donizetti, Debussy, Smetana, Kodály, Janáček, Hindemith, Alban Berg, Gian Francesco Malipiero, Witold Lutosławski, Milko Kelemen, Wittinger and Horvath.