Watch the Altered in C Minor online guitar lesson by Brad Carlton from Chord Studies: Slow Blues Progressions Vol. 1
This example is a slow blues in C minor with some very modern sounding chord voicings. Notice the altered chords, where a note from the standard chord has been replaced by a neighboring tone in the chromatic scale. You'll also run into some extended fingerings in this progression which make it a great workout for your fretting hand. Incorporate these changes into your daily wood shed and you'll see a lot of improvement in your left hand.