In the United States, The Legend of Zelda: Twilight Princess HD Sound Selection was only available as a pre-order option if you purchased the game from a GameStop retailer. In Japan and Europe, the Sound Selection disc was included in the amiibo bundle of the game. I don't know why the U.S. was limited to one outlet, not to mention as only a pre-order bonus but I suppose that's a discussion for another time..
The Disc consists of 20 tracks from the HD version of the game but to be honest, I can't really tell much of a different between the original TP soundtrack and this HD selection, which shows that they've done a good job recording the original TP. I haven't exactly sat down to compare them closely or pulled up the audio waveforms to analyze them but to me I would say that the HD version just sounds like a cleaner recording of the original--which isn't a bad thing. Twilight Princess is my personal favorite Zelda game so I wouldn't exactly want the soundtrack to be re-mixed or anything like that so I'm satisfied with a more sound version of the original tracks.
Now, being a "Sound Selection" obviously there are a fair number of tracks that have been excluded from the album but all of the major tracks are there, such as: Title Theme, Midna's Theme, Final Battle, Zelda Theme and Credits. So, while we're working on getting our extracted version of the soundtrack up an running, here's The Legend of Zelda: Twilight Princess HD Sound Selection to hold you over.