You're confusing frequency and resolution. Just because a set of music fits in a certain frequency range doesn't mean that all representations of it are equal. For example, consider this in graphical form:
Both have the same 24-bit color space. Both have the same blackest black and whitest white. Both have the same resolution. And yet one preserves more detail and information. This is the nature of lossy compression.
The sampling rate and frequency range are tied together though. The Nyquist rate says the sampling rate must be 2x the bandwidth. If you sample at 96KHz, the most bandwidth you'd get is sound waves up to 48KHz and still be able to accurately reproduce them. However, if human hearing taps out at 28KHz, then you could sample up to 56KHz and still reliably reproduce the same sound.
https://i.imgur.com/ZgU1bgI.jpg https://i.imgur.com/RZpbyyI.jpg
Both have the same 24-bit color space. Both have the same blackest black and whitest white. Both have the same resolution. And yet one preserves more detail and information. This is the nature of lossy compression.