This music manager thing really sucks. It was very buggy and hard to use. It didn't let me select what I wanted to upload as I expected, just took off after one of the Next button presses and started uploading everything in my My Music folder on my laptop, which contained instructional albums and things I didn't want to upload. I stopped it and then started doing one folder/album at a time but then for some reason it went back and uploaded everything. Now it's a mess. But I was thinking maybe I'll leave some of the instructional mp3s on the N7, but how do I indicate that they are not music and hence shouldn't be included in a shuffle of all of my music?