I mean, for example; Joseph Haydn’s “Nelson Mass” or Mozart’s Mass in C-minor. Were they ever meant for actual celebrations of the Mass, or were they just musical compositions that uses the form that the liturgy would use?
Most masses, with the exception of Gregorian masses and a few more contemporary works today, are composed in the classical genre. That means from sacred polyphony to 21st century. The western music scale (classical music) has much of its origins from the religious who began writing down the musical notations, first for Gregorian chant, then later expanding to what we know as classical music, then later to Jazz and so forth.
That said, although many classical music masses were meant for liturgy and others weren’t. For instance, Beethoven’s “Missa Brevis” was not composed for an actual liturgy, and I don’t believe it has ever been done during mass - although I could be wrong. Other composers throughout the centuries, especially during and after the Romantic period into the 21st century, have also taken the format of the mass to compose an orchestral religious masterpiece only meant to be performed in concert. Then you have works that were originally meant for liturgy, but were later found to be too operatic or secular-sounding to be acceptable for liturgy. One example would be Verdi’s “Requiem Mass”. Some have called it his most beautiful “opera”. This was done during mass in his time. I believe it was even done for his requiem mass when he died. But not long after in the early 1900s, despite its beauty, it was deemed as unsuitable for mass because of its operatic qualities.
When listening to masses composed during other periods of music such as the Baroque, Classical and early Romantic periods, one also has to realize that when these masses were composed, the orchestra was much, much smaller than what we would hear today in a concert hall, for instance. So the fullness of sound would have been different. I have attended mass a number of times in Salzburg, for instance, where they did both Michael Haydn’s masses and Mozart’s masses. They just have a small ensemble in the choir loft with the organ, choir and soloists. It doesn’t sound out of place in a huge cathedral or church with a small ensemble - probably the size of what it would have been heard in the time period. Give it the size of a modern day orchestra - that would be a different story.
Joseph Haydn’s “Lord Nelson Mass” or what he originally called as the “Missa in Angustiis”, would have been meant for a liturgy. Haydn composed masses for the Esterhazy royal family which would be used during the liturgies that the Esterhazy’s attended. This was one of the many masses that he composed for them while under their patronage.
Mozart’s “Great Mass in C-Minor” was also meant for the liturgy. It was first done in the Cathedral of his home town of Salzburg. His wife, Constanze, was one of the soloists. The Archbishop and Mozart had a huge falling out a few years earlier, so the two didn’t like each other much and although he recognized Mozart’s genius and beauty of music, the Archbishop didn’t like many of his liturgical music compositions. This was in part because he was resentful towards Mozart for leaving his patronage and going on his own to find other patrons. (Because of his genius, he was permitted as a child and teenager to travel throughout Europe and England to perform and also to grow as a composer, but he was also to be under the rule of the Archbishop and Mozart felt stymied by the musical culture in Salzburg which at the time was just a small city with not much around. Vienna was the place to go in Austria in order to grow musically. The break left a bad taste in both Mozart’s mouth and the Archbishop’s) It was also in part because the archbishops musicians were not up to the standards of the music (Mozart complained alot about the laziness and lack of musicianship of the Archbishop’s court musicians) and also in part because the Archbishop felt some of Mozart’s liturgical music was too “happy” and not reverent enough. Thus, the Archbishop rarely allowed his liturgical music done during mass in Salzburg, but did permit this mass to be done at the Cathedral while Mozart was visiting Salzburg.
On the other hand, the archbishop in Vienna absolutely loved Mozart’s liturgical music and permitted it for liturgy.
I mention the above story to show that what’s going on today in terms of people always complaining about the music is nothing new.