In the orchestra’s formative years, during which most of its members were not yet professional musicians, only the municipally-employed City Pipers were entitled to perform in churches, theatres and on important secular occasions of the city council. In 1773, however, the City Pipers had no alternative but to enlist the aid of musicians of the concert orchestra (not yet named Gewandhausorchester), as they were increasingly unable to cope with the growing personnel and technical requirements of the contemporary operatic repertoire. This was a pivotal step that was to fundamentally change the structure of music-making in Leipzig over the subsequent century. Alongside the concert orchestra (founded in 1743), a self-confident and high-quality theatre orchestra was established through its regular opera performances.
Due to fee cuts imposed by one theatre director, against which the musicians were determined to campaign, the members of the concert orchestra and those of the theatre orchestra signed a reciprocal agreement in 1786, which regulated the social conditions and workload of all the musicians. The contract was also open to those musicians who performed exclusively as part of the concert orchestra. Thus, the concert and theatre orchestras united to form an independent institution.
The founding of the City Theatre in 1817 provided for the introduction of a fixed salary for the 27 musicians of the orchestra for the first time. A permanent ensemble of singers was also established at the theatre, replacing the engagement of travelling theatre troupes.
In 1840, the City of Leipzig accorded the 27-member Gewandhaus and Theatre Orchestra official recognition as ‘city orchestra’, although this recognition in its individual form initially only applied to those musicians who undertook church music duties. It was not until 1881 that the city assumed responsibility for the entire orchestra.
From 1864, the theatre orchestra was released from its obligation to perform the music betwen the acts of plays, thus refashioning it from a general theatre orchestra into a specialised opera orchestra. With this decision, however, Leipzig's city council lagged behind developments in other cities by a good decade.
1868 saw the inauguration of the New Theatre. The larger stage and auditorium necessitated a larger orchestra, which was increased to a strength of 60 musicians. Only half of them, however, were permanent members of the orchestra; the remainder were lower-paid auxiliary musicians. This imbalance resulted in tension that led to considerable fluctuation in personnel. Nevertheless, both the Gewandhaus and the opera house orchestras benefitted from the numerous overlaps in personnel, as musicians of the concert orchestra had frequently augmented the theatre orchestra, thus guaranteeing the quality of the musical performance.
The strain resulting from the exertion of the performances of Richard Wagner's Ring cycle at the New Theatre in 1878 sparked new discussions regarding the status of musicians in the city. In 1881, the city council enacted legislation providing for social security for all musicians of the Gewandhausorchester, while formalising the orchestra’s obligation henceforth to serve in church, in concert and in the opera. Since then, the Gewandhaus, the opera house and St Thomas' Church have shared one and the same orchestra: the Gewandhausorchester.