Gritty Blues Rock Backing Jam for Guitar in A Blues... with a nod to ZZ Top. br br The basic progression is Am - F#m - E. So, if you are playing an A Blues Scale, make sure to mix in A Major over the F#. br br Video image derived from a photo by Thomas Leuthard. br Photo: flickr.comphotosthomasleuthard5665717830 br License: creativecommons.orglicensesby-sa2.