Learning riffs makes you a better guitar player

Although learning theory and scales and doing exercises is a great way to advance, learning riffs is still an integral part of becoming an awesome guitarist. Therefore I decided to make a collection of gnarly guitar riffs. They are going to be graded according to difficulty, and if you heard the song I am sure you will know more or less how difficult they will be.

Intermediate

Cream - Born Under a Bad Sign
Led Zeppelin - Good Times, Bad Times