mystery of the iPod

I am on my third iPod. I outgrew my first two because I had more music then they could hold.

My new iPod is a 160-Gbyte Classic, which I bought refurbished from Apple as a Christmas present to myself. I believe that 160 Gigabytes should hold all my music for a long time.

Although, I have added a few new tunes to my new iPod, it basically contains the same collection of tunes that I had stored on my old iPod.

Normally, I let the iPod randomly select the tunes it plays. What is interesting (my iPod “mystery”) is that I am hearing tunes on my new iPod that my old iPod never played.

Seems to me that my old iPod would randomly play a subset of the tunes it had in storage. Although the subset was probably immense, I did hear the same tunes repeated over time, but it obviously did not randomize everything because almost everything I hear on my new iPod is stuff I never heard on my old iPod.

Is my new iPod randomly playing a new subset of tunes or is it doing a better job of randomizing the collection?

By the way, for what it’s worth (or BTW FWIW), I have over 8,700 tunes stored on my new iPod. Also, my old iPod was a 30-Gbyte model.