Tracing the development of the music we call classical, it's impossible to ignore the social changes that played their part. Private performance for a patron evolved into the public concert. The long career of Joseph Haydn bore this out. Beginning as a court composer in one of the big houses of imperial Austria, he became hugely famous in the second half of the 18th century. He wrote a set of symphonies for performance in Paris. He spent a year and a half presenting new works in London.
We can see these changes too in that form of musical diversion that developed into opera. Magnificent singing had been part and parcel of church music, but there was no history of song on the stage.
In Rome, all forms of theatrical performance were banned for a time for religious reasons, and women weren't allowed to appear. This gave rise to the phenomenon of the castrati, the boy sopranos whose voices in adult life were artificially - and barbarically - preserved by what might euphemistically be termed medical intervention. They took the female parts in the early operas. Those would have been performed in private theatres, the preserve of the aristocracy.
Claudio Monteverdi, the man who's credited with creating the first operas, would have written for them. He was based in Venice, then an independent republic, when one of the wealthy merchant families there opened the first public opera house in 1637. This had a profound effect on the development of the art form.
If you wanted the punters to pay, you had to make sure you entertained them. So, with material tailored to the demands of the audience, opera took off in a new direction: less formal, more populist. The formula was successful. The art form flourished. Over the remainder of the century, there were at least four opera houses competing for business in the city.
But it would be over 100 years before the mould would finally be broken. The Italians may have invented it, but it was a Bavarian by the name of Christoph Willibald Gluck who opened the door to opera as we know it now.
He was done with the stylised conventions that had their roots in the ostentatious formality of the Baroque. What he wanted was the beautiful simplicity of a drama, told in music.
Orfeo ed Euridice, first staged in 1762, was the one that showed where opera was going now. Gluck was the great opera reformer, as The New York Times referred to him. He took his talents to France and had a huge influence on how opera developed there.
He was still drawing on legends from antiquity for his source material, but that was about to change as well. Tales of deception and intrigue came to dominate. The plots thickened.
As an example of where opera was headed, you've only to think of Mozart. In Vienna, he was treating audiences to The Marriage of Figaro, which has become one of the most popular operas around, a comic tale based on one crazy day where the aristocrats come off second best to the folk below stairs.
Though opera flourished right across Europe - Bizet's Carmen, Gounod's Faust, Wagner's Ring cycle, Dvorák's Rusalka, Tchaikovsky's Eugene Onegin - it was in Italy, its birthplace, that opera found its most prolific practitioners. From Rossini (The Barber of Seville, William Tell) through Verdi (Rigoletto, Il Trovatore, La Traviata) and on to Puccini (La Bohème, Tosca, Madama Butterfly), you have a complete collection of opera in all its glory.
George Hamilton presents The Hamilton Scores on RTÉ lyric fm from 10.00 each Saturday morning.