At the most basic level, they have obvious differences in tone classification. In modern Chinese, the tones we usually pronounce are divided into flat tone, rising tone, falling tone, which is what we often call 1234 tone. In classical poetry, although the tones of Chinese characters are also divided into four tones, they are divided into four tones: flat, upward, far and progressive.
Knowing the different classifications of Chinese tones between modern Chinese and ancient poetry, let's take a closer look at their similarities and differences in pronunciation. Although the names are different, the tone of Yin Ping and Yang Ping we use today is basically the same as that of classical poetry. In other words, even tones in classical poetry actually include one tone and two tones in modern Chinese. Secondly, the rising tone and most falling tones in classical poetry are basically consistent with modern Chinese.
Having said the similarities, let's look at the differences in pronunciation. As mentioned earlier, the flat tones of classical poetry include flat tones and modern Chinese flat tones, and the rising tone and falling tone are roughly equivalent to the rising tone and falling tone respectively. Careful friends will find that the only thing I didn't mention was Rusheng in ancient poetry. This is because Rusheng in classical poetry is a very special concept. In classical poetry, Rusheng is divided into one category, but in modern Chinese, Rusheng characters are divided into all tones of modern Chinese. In other words, each tone contains ancient entering tone words. For example, in generations? Uncle? And then what? Bo? It is Rusheng, but in modern Chinese, it becomes one tone and two tones respectively.