Music Theory for Harmonica Players

Do you need to read music to play harmonica? An introduction to music theory for the harmonica.

Music Theory in 16 Minutes (harmonica version).
What are positions on harmonica?.
How does the Circle of Fifths work?.
Do you need to read music to play harmonica?.
Beyond The Blues Scale: adding contrast to your harmonica solos.
Introduction to 1st position blues harmonica lesson.