Watch the 1st and 2nd Position online guitar lesson by Annie Raines from Blues Harmonica Blueprint
Now we’re looking at the scale not as a series of letters but as "degrees," a set of fixed intervals that relate to the key we’re playing in. In the western 12-tone scale, those intervals are 2nd, 3rd, 4th, 5th, 6th and 7th, and also flat 2nd (or sharp 1), flat 3rd (or sharp 2nd), flat 5th (or sharp 4th), flat 6th (sharp 5th) and flat 7th (sharp 6th). (You can also keep going with the count and call the octave an "8th" and the next whole tone a "9th" instead of a 2nd, a 10th instead of a 3rd, etc., as you continue to relate to the root note).
When you play two notes at once, the notes vibrate at different frequencies and the peaks and valleys of the sound waves interweave and occasionally line up. This crisscrossing of peaks and valleys creates a beat pattern we call harmony. Any of these intervals creates a unique harmony when played against the "1" and that harmony can be created in any key you’re playing in. For instance: if you play a C and an E together by blowing on holes 4 and 5, that interval is a 3rd. If you play a G and a B together by drawing on holes 2 and 3, that interval is also a 3rd. Scale degrees are ideal for describing most simple melodies and basslines, since you only have to memorize one set of numbers instead of 12 progressions of lettered scales.
Here I demonstrate "Taps" in both straight and cross harp positions, but for more of a "party" atmosphere, you can use the same 4 notes to play "Reveille."