Watch the Rainbow Power online guitar lesson by TrueFire from Play Rock Guitar 8: Advanced Rhythm Approaches
Rainbow Power - Rhythm #39 is a video guitar lesson presented by Jeff Scheetz and is sourced from 50 Blues Rock Rhythms You MUST Know.
Some of the classic rock bands like Rainbow, Montrose, and maybe even some Black Sabbath used a heavy chord based riff to sound ominous. This riff is a way to take a shuffle beat, but rather than doing a normal "blues" thing over it, you can heavy it up a bit and make a rocking tune. Kick on the fuzz for this one and you will be in 70s rock heaven.