Watch the Adding a Second Voice online guitar lesson by Brad Carlton from Guitar Lab: Boogie-Woogie
You will learn a movable form of the boogie-woogie rooted of the 6th string in this lesson. An additional higher voice consisting of the 3, 4, and 5 is applied to the lower 5, 6, b7 move. I have labeled this lesson "adding a second voice to the boogie-woogie" to show how to build on the basic two voice form. I am disregarding the root in the bass as you may play these patterns with or without that lowest voice.