For a harp, you can use it for any key. The channels run the same way. The 4th hole, when blowing is the root, draw(inhale) is the second of the scale, the 5th hole,when blowing is the third. So on an A harp that would be in order, A, B, C#. On a C harp, C, D, E. The really low, and really high notes are somewhat different. -macg1 | 1/10/2006 |