How were ancient poems, songs and classics published and circulated in ancient times?

Your question is very good. In fact, this is an ancient communication problem, which involves a lot of knowledge. I can only simply say:

First of all: there were newspapers in ancient times.

The earliest paper newspaper (appeared in 1980s) and the earliest printed newspaper (appeared in 10 century) in the world were both produced in China. Initially limited to official newspapers, there were unofficial newspapers after the Song Dynasty. The official newspapers in Tang Dynasty and Song Dynasty both have special distribution agencies.

Secondly. The spread of poetry books actually involves the problems of ancient publishing institutions:

The spread of ancient books in China was originally copied by people for their own use; Later books were copied and sold, and books began to become commodities. People's demand for books has increased, and bookstores selling books have also appeared. After the invention of block printing, with printed books, the formal publishing industry began to appear. After middle school in Tang Dynasty, folk publishing engaged in block printing has become very common in Sichuan, Jiangsu, Zhejiang, Anhui, Shaanxi, Henan and other places. At the end of the Tang Dynasty, Chengdu, Sichuan became the center of block printing in western China, and the block printing industry was very prosperous. At that time, Chengdu Bookstore sold mostly printed books.

At first, woodblock printed books were only popular among the people, and some calendars, rhymes, songs, elementary school calligraphy books and Buddhist scriptures were also published, which were widely needed by the citizens. It was not until the 1930s of 10, that is, the late Tang Dynasty of the Five Dynasties, that the official officially used block printing to print Confucian classics. From 932 to 953, two classic and classic definitions of1were printed successively. This is the earliest publishing undertaking sponsored by the government in the history of China. These books were engraved by imperial academy, the educational administrative organ and the highest institution of learning and publishing in the country at that time, and were later called "supervising books".

The publishing business sponsored by the government in Song Dynasty was very prosperous. In addition to imperial academy, the central publishing institutions also publish books, such as Chongwen Academy, Secretary Supervisor, Secretary Supervisor, Correction Medical Books Bureau, etc. There are many local publishing institutions, and books are published in yamen, state schools, military schools, county schools, county schools and academies. Books published in imperial academy are allowed to be rented and printed by the folk publishing industry, but they have to pay "rental money". For locally rented printed books, it is also stipulated that the quantity fee and rental fee must be printed in front of the book to prevent booksellers from arbitrarily raising the book price. For books published by the people, copyright protection measures have also been taken, and publishers can apply to the government for protection. If someone else's copy is found, it will be "chased and destroyed, and the crime will be executed." Some books in the Song Dynasty are engraved with the words "addressed to the boss, not reproduced", which can be said to be the origin of the "copyright page" of books.

Therefore, the ancient publishing industry was also very developed. As for some poems and songs, some are passed down orally and then sorted out and published.