If you try playing the highest octave of the C major scale starting on hole 7, you will find that the note B (the 7th degree) is missing, so you get C (1), D (2), E (3), F (4), G (5), A (6) C (8). The following example contains three octaves of the C major scale (apart from the missing B note), which is the complete range of the C harmonica. All ten hole diatonic harmonicas have a range of 3 octaves regardless of what key they are tuned to. When you play in the key written on the harmonica (in this case C) instead of cross harp, you are playing in first position. As you learned in lesson 2, cross harp is often referred to as second position.