In order to play third position on the harmonica the 4, 5, 6, and 7 holes draw will allow you to play in a minor key. In the case of the C harmonica this would be D minor. Once again, if the band is playing in D minor and you wish to play along on your C harp, you would use third position, or holes 4, 5, 6, and 7 draw.
FIGURE 8-6: Third-position licks
It's important to know that, whichever position you play in, you will need to be aware of the key of the song you are playing. From picking the right harmonica for the job to knowing whether you're playing in a major or a minor key and which notes are in the scale of that key, giving your playing this level of attention will improve your ability to play harmonica solos that make sense over the chord progressions you're working with. In addition, being aware of some of these simple rules of music theory will help you express your musical ideas verbally to other musicians, and to understand what they are talking about when they try to communicate with you.