The string quartet performed repeatedly in Milan since 1939, first at the Conservatorio Giuseppe Verdi, then in 1949 in the auditorium of Università Cattolica del Sacro Cuore and in 1951 in the Teatro Excelsior.
During the Second World War (1 to 4 June 1943[4]) the quartet also gave [5] Nazi propaganda concerts in occupied France (Bordeaux, Poitiers and Angers).
[9] The 1951/52 season was preceded by the Beethoven cycle in Munich and Stuttgart, and later by all of the composer's string quartets in the Mozarteum in Salzburg and in the Palazzo Pitti in Florence.
At his side were Josef Krips (1929–1933), Jost Raba (1934–1938), Hermann Hubl (1939–1951), Otto Schad (1951–1953) und Ruth Wagner-Nielen (1953–1965) as 2. violin, Rudolph Nel (1929–1933), Walter Trampler (1934–1938), Hermann Hirschfelder (1939–1951), Franz Beyer (1951–1953 and 1962–1965), and Walter Müller (1953–1962) as violist and Hans Schrader (1929–1933), Ludwig Hoelscher (1934–1938), Hans Münch-Holland (1939–1953) and Irene Güdel (1953–1965) as violoncellist.
The Strub Quartet was specialised in the classical and Romantic repertoire as well as more modern music, for example by Max Reger and Paul Hindemith.