The Philharmonisches Staatsorchester Mainz (literally: Philharmonic State Orchestra of Mainz), is the resident orchestra of the Staatstheater Mainz. In addition to musical theater and Tanztheater (concert dance) youth symphony and chamber concerts are part of the activity of the orchestra. It is one of the three symphony orchestras of Rhineland-Palatinate. Since September 2011, Hermann Bäumer has been principal conductor.
Under Cardinal Elector Albert of Mainz, who obtained the Electorate of Mainz in 1514, and in 1518 was made a cardinal at the age of 28, the orchestra is first mentioned as electoral court orchestra. The first verifiable conductor, Jan le Febure took up its duties at the Mainz court in 1601. In the following years the musical arrangement of numerous imperial coronations is evident, whereby the Mainz electoral court orchestra already gained early supraregional recognition. For example the orchestra performed in 1612 during the coronation of Matthias, Holy Roman Emperor. At the beginning of the 18th century, Elector Lothar Franz von Schönborn initiated the formation of a secular orchestra. This included the extension of the strings by woodwinds and horns. Elector von Schönborn was also setting records in the form of a decree to introduce a court musician.
In 1777, a size of 35 members of the orchestra is documented. The first permanent theater in Mainz was built in 1760. Elector Emmerich Joseph von Breidbach zu Bürresheim allowed his musicians to participate in opera performances in this theater. Thus, the orchestra was now categorized as an opera orchestra. Only a few years later, elector Emmerich Joseph erected an Electoral Comedy House (Kürfürstliches Komödienhaus) at the avenue “Große Bleiche”. He subsidized the musical performances and made his band available for the opera. In the first musical almanac of 1782, the Mainz court orchestra was now listed among the finest in the territory of today's Germany. The opera itself made its mark during the following years, especially with Mozart's works. For example Mozart's Don Giovanni was performed as a premiere in German language in 1789 in Mainz. Besides the Mozart family grand tour, Mozart stayed several times in Mainz, and gave concerts with the orchestra. The opera flourished in Mainz at the end of the 18th century and was considered one of the best in Germany. The number of employed musicians in the court orchestra increased to 48, which was remarkable for that time. Elector Friedrich Karl Joseph von Erthal had upgraded the theater since the National Theatre. A few years later, during the War of the First Coalition, the comedy house was destroyed during the siege of Mainz (1793). The elector disposed the conversion of his stables to be used for a theater. It serve as a venue for the next 40 years.