Are you referring to the quality of the sound of the music, or the connotation of the music itself? If you are just asking about the sound quality, it would be better to explain it to you. Here is a simple knowledge. The music we usually listen to is heard by sound waves in different frequency bands stimulating the eardrums. And what we usually call low-quality music is compressed sound. What content does it compress? There are many, but one is very important, and that is some frequency. Frequencies that are difficult for our human ears to distinguish, such as ultra-high audio and ultra-low audio. You can do an experiment yourself, download a low-quality music, play it on a good speaker, and turn the speaker's adjuster to the middle. You'll find that you can barely hear the subwoofer in the music, and the treble at the climax doesn't sound satisfying either. That's why it's compressed.