Sandra, it is possible to play high rez files on itunes.
However, you have to convert the files to wave using a
converter program such as from this web site:
http://www.dbpoweramp.com/
I tried a few free samples at HDtrack web site and
they do work in itunes after conversion and are still
high rez quality. The People at HDtracks did tell me
that you can play them on your ipod. However, these
files will not transfer to my ipod even though they do
play on my computer.
Bummer, I really wanted to try out this high rez media.
Maybe it works on newer ipods.