Right - we're at the final stage now.
Our final alteration will occur in bars 9 and 10 of our progression. We're going to use a classic blues trick using two chords as substitutions for the Dm9 and Em7 already in those bars.
In bar 9 we're going to insert an F9 chord. This is the classic James Brown-esque funk chord - a sound I'm sure you'll recognize. This is going to lead very nicely in bar 10 to an E7#9 chord otherwise known as the Jimi Hendrix chord. Apparently Jimi never played this particular voicing but did use a similar shape containing less notes, however, this shape has been given his name and most guitarists recognize it.
This E7#9 leads really nicely back to Am9 and occurs again in bar 12 giving us a final bit of tension before resolving back to the Am9 chord at the beginning.
We could go much further enhancing and substituting chords in this progression but I'm sure you'll agree this humble progression has already come quite some way.
Enjoy playing through these progressions and for an extra challenge try transposing them to other keys or soloing over them using the relevant scales (A minor pentatonic will work with all these progressions but there are other ways to approach this which I'll cover in future tutorials.)
Good luck!
See you soon,
Tom