As a 62 year old pre-boomer with an eclectic taste in music, I use a 40gb iPod for workouts. Using the shuttle mode with an 11,000 song library, consisting of everything from Glen Gould to Hank Williams, Stevie Ray Vaugn, Cuban, Cajun, Caribbian, Willie Nelson, Verdi, Mozart and lot of other stuff in between, I am constantly delighted with the serendipity. If something comes along that doesn't fit the moment or the mood- hit the advance button. At the same time you can build a new list of what you find to be just right. iTunes on a Mac or PC with a large hard drive and a USB DAC connected the the main system is a fabulous combo, and the Playlists you can generate can be exceptional. Everyone has their own musical preferences, so best to find your own.