If one were to walk into a "public" music performance in the Baroque/classical era, be it an opera, concerto, mass etc., what would one expect to see? Would the audience be mainly wealthy or nobility, lower class commoners, or a mixture of both? Would the audience be excited and involved, or calm and subdued? What would the concessions/facilities look like, if any? How would these performances compare to a modern pop/rock concert, or theatre performance?
How familiar would the audience be with the performers, composers, story, and music beforehand, if at all?
Related: how were "famous" stars of opera, or instrumental virtuosos treated by the general public? Did they have a large dedicated following?
Sorry for the many questions, this is just a topic I've long pondered! Thanks in advance.
Excluding churches, baroque period music was mostly for the aristocracy in their palaces, with the orchestra/choir size depending on how wealthy a court was. For composers involved, they were considered servants under the nobility. Outside of that, there are still performances for the public, usually in taverns, universities, and coffeehouses.
While opera was also a venue of entertainment and flattery for aristocrats (like singing about the Greek gods to symbolize the royalty), public opera houses were also in existence. However, outside of exceptions in cities like Hamburg, Leipzig, and London, it took time for them to catch on outside of Italy.
In terms of star power, castrati (male singers, usually soprano, who were castrated before puberty) were especially popular and received the highest pay of any musician at the time because of how unique their voices were (similar to a female, but still quite different); it was not uncommon for poor families to allow their sons to be castrated with the hope that they become opera stars.
Unlike the baroque period, the classical period's audiences saw a larger middle class background as people had more access to money and education than ever before. Since they could not attend palace concerts, they were instead able to hold public concerts, such as the Concert des Amateurs in France.
Source: Music: An Appreciation by Roger Kamien