Cecil Aronowitz was one of a select group of London-based classical musicians who were closely involved with the composer Benjamin Britten. While the violist's career was replete with stunning performances, important recordings, and gala events, his most profound influence may have been as a teacher. During his tenure at the Royal College of Music, he was personally involved with the training and instruction of many important musicians, particularly in the area of chamber music. Nevertheless, he was much appreciated as a chamber music player. He played as the Amadeus Quartet's fifth player when the group's repertoire included quintet music. He also performed with the Croxford Quartet. Yet as challenging as the chamber quartet or quintet repertoire may have been, Aronowitz had a desire to make a positive change in another, even more complicated, area of classical repertoire. In 1950, he rounded up some dozen top-flight players to commit themselves to the Melos Ensemble, an expanded chamber group. The idea was to perform larger chamber works such as the Schubert and Mendelssohn octets, the Beethoven Septet and the Ravel Introduction and Allegro. As there were very few similar ensembles working regularly, the Melos Ensemble had no problem establishing itself as la leader in the performance of this type of repertoire. Yet diminishing competition was not the principal reason for the group's popularity among musicians, composers, and audiences. Aronowitz was a perfect leader, unassuming and hard to ruffle while always taking care of business. Under his supervision, the collection of brilliant players were known to produce meticulous as well as heartfelt performances. The group was heavily involved in the premiere of Britten's War Requiem in 1962, one of several pieces by the composer in which the writing for viola was designed specifically for Aronowitz. The relationship with Britten led to many other premieres of new chamber works, including Birtwistle's Tragoedia and Maxwell Davies' Seven In Nomine, both in 1965. Other members of the Melos group included violinists Emanuel Hurwitz and Ivor McMahon, cellist Terence Weil, bassist Adrian Beers, clarinetist Gervase de Peyer, and clarinetist and bassoonist William Waterhouse. The group performed regularly internationally, and toured the United States for the first but definitely not the last time in 1966. There were many broadcasts on the BBC for this group, and more than fifty recordings have been commercially released under the Melos Ensemble name. Aronowitz kept the group going following the death of close collaborator McMahon in 1972 and the departure of several others. Melos regrouped with eight original members. The ensemble gave its twenty-fifth anniversary concert in Queen Elizabeth Hall, London, in 1975. The violist also made many appearances as a guest soloist with orchestra. He recorded Hindemith's Trauermusik for viola and strings for EMI, with the English Chamber Orchestra, the Berlioz composition Harold of Italy, with the York Symphony Orchestra, and Ralph Vaughan Williams' innovative Flos Campi, with the Jacques Orchestra and the Choir of King's College, Cambridge. He also performed in the premiere of Arthur Butterworth's Suite, Op. 13, for viola and cello in London in 1951.