The first things we know about the music history, are, of course, as old as the idea of humanity itself. People had always the need of music, and music had always the need of people. We can't exactly tell how it started, because, as far as we are concerned, it always existed in some form.
Usually the first era taught in music history, is ancient Greek music, and medieval music. But these musical eras are way past us, and it's really difficult to relate to them. So we 're going to talk more about more recent eras
Starting with the musical period or Renaissance. Personally, my favorite. One of the main composers of that era is Giovanni Pierluigi da Palestrina. His style, like music was in a more general way in that time, was mainly counterpoint. Harmonic progressions were not yet developed logically that early in history. It all started of course, with the human voice: singing! The development of singing, and, of course, the development of polyphonic singing, was slowly taking its place into the musical world.
Then along came the Baroque period. Were counterpoint had its rightful place in music, in the hands of Johann Sebastian Bach, and Claudio Monteverdi, and many other elegant composers. The Baroque period is one of the favorite of many many musicians across the world, like me. And with a right mind, because that time's music was heavenly!
The next step, as one would imagine, was the development of harmony, and the establishment of logical harmonic progressions. A musical language morality, if you will. That happened in the Classical era. Of course there is a reason it's called Classical. We will talk about that later. The most elegant composers of this period were Joseph Haydn, Wolfgang Amadeus Mozart, and Ludwig van Beethoven. Beethoven, was also the passing point, in a way, to the next musical era:
The Romantic! There we have even more extended research of the harmony, and of course the musical form. With the most known composers being Frederic Chopin, Johannes Brahms, Ferenc List, and many others. That music focuses especially into extended mood changing and a sense of adventure and deep feelings. Although, even with music being even more explored and developed, the public which it attracted was becoming smaller by the day. And that is because it gradually passed the understanding capabilities of the common man, without any music training.
That left the Classical period being the most prominent in our ears, and that's the reason it's called Classical. Because, even today, so many years after it, the common man's ear is still conquered by that music, probably because it was the last major literature of music, that he could understand pretty good.
Nowadays people that are interested in contemporary music, are a very special and select group, consisted 99% of musicians. No man with no music training can understand contemporary music, and that's a shame.