By the time Bridge left the Royal College of Music in April 1903, he was already noted as an up-and-coming viola player, not only in College circles but also in the profession, and it was therefore not too difficult for him to find employment. He belonged to several theatre orchestras and, for a time, the orchestra of the Royal Philharmonic Society. Yet, for Bridge, the most rewarding playing was not in orchestras but in his favourite genre, chamber music. In all, he played regularly in three string quartets - in the Grimson Quartet as second violin, and as the viola player in the Motto and English String Quartets. While the Grimson and Motto Quartets made considerable reputations for themselves, the English String Quartet became one of the most important British chamber ensembles of its time. Its repertoire included both a representative selection of Classical and Romantic string quartets, and such contemporary British works as Friskin's Piano Quintet and compositions by Bridge. It also included an enterprising group of French chamber pieces - Franck's Piano Quintet, Fauré's First Piano Quartet, Debussy's String Quartet and both Ravel's Quartet and Introduction and Allegro. Much of the work was in London, but in the early days both the Grimson and English String Quartets visited the provinces frequently, and the Grimson made a tour of Belgium and France during the autumn of 1907, including performances of Bridge's three Idylls in its programmes.
An event that proved particularly advantageous for Bridge's reputation as a viola player occurred in 1906. During a series of concerts given by the Joachim String Quartet devoted to Brahms's chamber music, extra players were required for the two sextets, and for the performance of one of these (on 26 November) Bridge was chosen. It was something of an ordeal to be playing with such an august quartet party, and at the first rehearsal, Bridge 'was conscious of three beards turned towards him, anxiously ascertaining his powers and suitability'. Bridge reported to Ivor James afterwards that:
[Robert] Hausmann the cellist had confided to him that Joachim, who was now nearly blind, played everything almost by heart and had forgotten the existence of one bar in the G major sextet ... And that they did not like to remind him of it, so ... they all skipped that particular bar!1
It is interesting to note that Bridge's inclusion in the Joachim quartet party was considered so prestigious that its importance was over-emphasized, and details of the event were nearly always stated incorrectly. The indisposition of Emanuel Wirth, the quartet's viola, was given repeatedly as the reason for Bridge's inclusion, yet this was not the case. When Wirth became ill he was replaced not by Bridge, but by Karl Klinger. Then Alfred Gibson was invited to play second viola in the first Brahms sextet and Bridge in the other.