Just FYI, “high res audio” is a fraud, a marketing gimmick based on pseudoscience. It is not physically possible to hear frequencies that high. A standard CD already captures everything within human hearing range and then some, after you’ve reached the age you’re likely to care about audio quality your hearing won’t even be able to reach that, and the vast majority of music does not make use of anywhere near the dynamic range supposedly offered by this “higher resolution.” All it does is waste disk space. It’s useful only in studios for purely technical reasons, utterly useless for the end consumer.

This explains it better than I could:

https://people.xiph.org/~xiphmont/demo/neil-young.html

As for Star Wars, I would advise seeking out the 1993 anthology CD set for the best sound and more complete versions of the OUT soundtracks.