by Seth Rosen - Lesson I in a series
Seth Rosen has played mandolin for nearly 30 years. A multi-instrumentalist (guitar, bass and violin too) he has performed with a wide range of performers including: Blues legend Howard Armstrong, Swing greats Bross Townsend and Rusty Mason, Songwriter Si Kahn and Western musicians Liz Masterson and Sean Blackburn. He currently plays in two northeast Ohio Bands: Crazy Rhythm playing swing and western swing, and The Suspenders! playing jump blues & roots rock. He has been on the staff of the Augusta Heritage Center's "Swing Week" for six of the past eight years as both a dance musician and a swing mandolin instructor.
In this lesson, we take the classic form of a 12 bar blues and learn some concepts about chord substitution. I have not included any chord diagrams for two reasons. First, there are plenty of diagrams elsewhere on the board that you can use (virtually all these chords can be three note moveable chords). Second, perhaps more important, figuring out how to get from charts like these to the right chord voicing is part of the lesson. If you have questions, post them on the discussion section of the Mandolin Cafe bulletin board and I (or the other knowledgeable players that gather here) can answer them.
We will use the Count Basie blues classic "I Sent For You Yesterday" as an example. Though it is usually done in Ab, I put it in the Mandolin friendly key of G.
The first example is using the three chords we all know and love...G (I), C7 (IV7) and D7 (V). Go through this sample and try and get the swing feel. Use the swing rhythm from an electronic keyboard if you have one.
Next we make a simple substitution...changing sevenths to ninths in some measures. This works because a 9th is almost identical to the 7th. Listen to how the sound of the 9th leads into the next chord. That is why when there are two measures of a 7th chord, it is the second measure that I have substituted for. Sometimes you might substitute both measures.
Chart number 3 uses 9ths also. In measure 6 we use a C# diminished instead of a C7...why does that work? The notes of the C#dim are: C#, E, G & Bb. Other than the C# they are the same as a C7... the C# is an ascending bass line that leads your ear to the G... play that phrase through a couple of times and listen to the difference.
We also substitute a Dm7 for a G7 and and Am7 for a D7. Why does that work? Again, let's look at the notes of the Dm7: D, F, C... it has the IV V and bVII of a G7. Why does the Am7 work for a D7...same reason. Finally we have a turnaround to substitute for the last two measures... you know why the Am7 works, but what about the G#dim.... like the C#dim above its almost the same chord as the G7 but it has G# instead of a G which in this case gives us an ascending bass line up to the Am.
Finally, version number 4 builds on 3 with the addition of some "passing chords"...that means when you pass from Dmin7 to C7 you make a stop on Db7 which only works because you resolve it in the C7. Find the other two passing chords in this chart (hint: flat chords in a sharp key). Finally we add an augmented chord to substitute for the V (D+ instead of D7)...this works cause it leads to the I chord, you wouldn't do it in the end of a song... often as a turn around... or as here leading to a turn around.
Good luck and feel free to post any questions on the discussion board under jazz, swing etc.
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