Most of the Norteña, music that has been popular for many years is based on the major scale. We rarely use any notes from outside the scale except as accidentals (passing notes).
if you want to play some of the more advanced styles, especially the Tejano music played by artists like Flaco Jimenez or
Albert Zamora, you will need a bit of understanding of the scales they use.
Lets look at the Key or G.
and Blues rely heavily on the dominant seventh chord.
Instead of playing a G, it is very common to use a G7 as the first
chord in a song.
What are the notes of a G7 chord?
G B D F
By lowering the seventh note in the scale and adding it
to the G major chord you get a G7.
But that changes the scale. If you lower
the F# in the G major scale, you now have the same scale as a C major scale, but starting on a G note.
the scale from the 4th interval of the Key when you play a rock or blues style song.
In G, use C
In C use
In F use Bb
In D use G
In Bb use Eb (Good luck on that one)
This is interesting in that Harmonica players do
exactly the same thing. Blues harmonica players use a C harmonica when they play
blues in G. Unfortunately, they can bend notes but we cant. Why is this important to us? In case you havent noticed, the
Diatonic Button accordion is really just 3 harmonicas in a box, with buttons and a bellows.