What is the poem about the height and scarcity of songs?

The lyre plays a cool tune and listens carefully, like a tumbling pine tree. Although I like this ancient song very much, most people don't play it today.

From Liu Changqing's Playing the Piano.

In other words, this song should be only in the sky, and it is rare to hear it on earth.

Explanation: The melody is so profound that few people can sing along with it. Old fingers are hard to find. Metaphorical speeches or works are not popular now, and few people can understand them.

From: The Warring States Period Chu Song Yu's "Ask the King of Chu": "There are few merchants carving feathers, and there are many miscellaneous signs, which belong to the country and are harmonious. It is its high music and rare harmony. "