It was not until 1771 that the musicians applied for the establishment and performance of so-called concerts for the amusement of the respectable people, which had not existed in this form in Aachen before.
On the occasion of the inauguration of the new municipal theatre on 28 March 1825 as part of the eighth Niederrheinisches Musikfest, which was held for the first time in Aachen, the orchestra including the choir was increased to 422 members in order to be able to perform under the direction of Ferdinand Ries.
From then on, the orchestra regularly took part in this music festival, which was held until 1958, alternating between the cities of Elberfeld, Düsseldorf, Cologne and Aachen.
From this time on, the orchestra also offered regular winter subscriptions, musical project weeks and, from 1910, the well-known spa concerts.
In the same year, it also resumed the spa concerts which had been interrupted during the war, and from 1958 it took over the musical arrangement of the Aachener Heiligtumsfahrt [de] again.
Some later very famous conductors like Fritz Busch, Herbert von Karajan and Wolfgang Sawallisch started their career in Aachen.