[1] Isaacs had an absorbing interest in chamber music, and from 1929 until 1943 often played with the Griller String Quartet, performing quintets by Brahms, Schumann, Dvorak, Elgar, Bax and Bloch.
He also performed many recitals at the Wigmore Hall with members of the Griller, and with Jean Pougnet, William Primrose, Lionel Tertis, Elsie Owen (violin), Winifred Copperwheat, Maurice Eisenberg, Douglas Cameron (cello) and others.
James Whitehead and Vivian Joseph also took the cello chair in the Trio.
[3][4] Arnold Bax also wrote his final chamber work, the Piano Trio in B flat, for the Isaacs Trio, who performed it at the Wigmore Hall on 21 March 1946.
[8] With Dennis Brain he premiered Peter Racine Fricker's Horn Sonata, Op 24 at the Conway Hall, on 20 March 1955.