Of the three different scales discussed above, the one place it's possible to play the full major scale in the key of the harp is between holes 4 and 7. This is achieved by playing the following pattern:

4 blow – 4 draw – 5 blow – 5 draw – 6 blow – 6 draw – 7 draw – 7 blow

If you're playing in the key of C and you want to play a major melody, such as “When the Saints Go Marching In,” you would have to play it between holes 4 and 7.