Two great Beatles tracks for you to soak in, now that we are all studied up on Beatles recording technology, (i.e. For the music geeks):
I Want To Hold Your Hand (Offline)
Tomorrow Never Knows (Offline)
The prior was recorded using a 4-track in 1963, the latter was recorded three years down the road. Even if you've heard these tracks 1000s of times before, you should download and listen again.