It became popular for music writers to name their own musical works in the early 18th century (the period from the end of Classicism to the beginning of Romanticism).
As for many classical music works that have been handed down, the names we are familiar with such as "Destiny", "Moonlight", and "Pathetique" are actually given by later generations, not by the musicians themselves. As for the work numbers, basically the work numbers of music before the Romantic period were all given by later generations in order to organize and classify them more standardizedly, and were not given by the musicians themselves. The arrangement of work numbers depends on the situation of different people. Some people assign work numbers according to different music genres, and some people assign work numbers according to the order of publication time of the works.
For classical music lovers, they somewhat despise songs, especially pop songs. The difference between the two is probably the difference between Yangchun Baixue and Lower Riba people. The works completed by the senior masters of classical music always have a code name, right? It's like giving birth to a child who always has a name. You can call him Zhang Mude or Zhu Wusi. Otherwise each child produced would be indistinguishable. From my understanding, it doesn’t matter whether it’s the nature of instrumental collaboration or the number and name of your own work. At most, a composer can define a spatial range for a work within the imagination of the audience; this includes Beethoven's "Destiny", "Hero" and "Pastoral". Most composers still don't make this specific definition; it's best for viewers to understand it on their own. The wild and unconstrained thoughts will make you feel that the lingering sound lingers for three days, and you will not know the taste of meat for half a month! This is the true spirit of classical music! If you are Zhong Ziqi, you will understand that it depicts mountains and flowing water. If you are just showing off, you can shake your head to the rhythm without saying a word, and no one will think you are a fool. But don’t be like the so-called half-hearted people in popular music who dare to brazenly claim that they are engaged in music by putting together a few so-called howling songs. You can only mess with the music, and that’s no fun!