I. The Major Scale
A. "Dough, the stuff that buys me beer..." Ask if everyone is familiar with do- re- mi. This is the major scale.
B. Show the major scale on a keyboard, starting on C. Label the whole steps and half steps. Explain what they are.
C. Show the major scale on a keyboard, starting on G. Show that the whole step/half step pattern is the same, but different notes are "playing the parts" of do, re, mi and friends. Also that F# has been called in to maintain the pattern, and that this is indicated using a key signature.
D. Perhaps show a few more scales.
E. Summarize how to parse "The key of C Major" - it is a major scale (do re mi, pattern of whole and half tones), starting on C (the key).
II. The Minor Scale
A. Show the major scale starting on C.
B. Explain that by starting on A (la) and going up, you get the minor scale, a different pattern of whole tones and half tones.
C. Show minor keys corresponding to major keys shown in I.C. and I.D.
D. Summarize how to parse "The key of A minor."
III. Why are the major scale and minor scale different when they use the same notes?
A. Point out that C Major and A minor share a key signature. Why aren't they the same?
B. Answer: they have different patterns of whole steps and half steps. Yeah, but so what? They are the same notes!
C. Bring up the concept of finals (ending notes) and cadences (ending series of notes) and melodic structures in general. Point out that, as they traverse the scale from do to do or from la to la, the whole tone/half tone patterns are different. This is why they sound different.
D. Play a song in a Major key and a song in a minor key.
IV. What's so special about do and la? Why are there only a Major scale and a minor scale?
A. Nothing! The missing scales are the ancient modes.
B. Describe the modes by their whole tone/half tone patterns and their starting scale degree (re, mi, fa, etc) and play examples of each. Point out that they are often almost the same as the Major scale or minor scale.
C. Explain that historically, these modes (especially Dorian and Mixolydian) were the most popular scales for composing music, just like the Major and minor scales are today our most popular scales.
D. Finally, point out that just like you can have the Key of C Major and the Key of G Major both be Major scales, you can also have the Mode of D Dorian (or D Dorian mode) and the Mode of A Dorian. "Dorian" describes the pattern of whole tones/half tones you get when you start on "re." The letter (D or A) tells you what note is "re".