There are plenty of resources available to help students learn traditional, Western music theory. Some of my favorites:
Students should have a good grasp on the “why” and “how” of the music that they make. Knowing the structure of a piece can lead to a richer performing experience. Deeper understanding of harmonic function can inform improvisation and composition. There are very few arguments against teaching music theory to students.
One of the major barriers for me as I attempted to introduce improvisation and composition in my classes was theory. I always assumed that I needed to provide students with a strong harmonic foundation before digging into these topics. Then I would attempt to teach harmony as I had learned it in school, on the white board and with a piano. This was before we had even played a note. Big mistake. Students need to learn through doing. If they can play their instruments they can begin to compose and improvise. After they have experienced these things then it is time to broaden their horizons by introducing theory.
For example, I am a fan of Jamey Aebersold’s series of books. Anyone teaching jazz in school needs to have a good representative set of these play-along texts available for their students. One of my favorite things to do, either in class or during free time, is to play along with students to a track in one of these books. Each book contains several jazz pieces with the melody and chord structure written out for each instrument family (C, Eb, Bb, bass clef). The companion CD contains a full jazz rhythm section playing the piece multiple times through. The idea is that you play the melody, or head, and then improvise over the other choruses. Its tons of fun and can lead to some really creative thoughts from students. When introducing a particular piece, say Miles Davis’ “Freddie Freeloader”, we would jump right into playing the head and then we’d do some call and response over the chord changes. The piece is basically a blues so you could stick to the “blues scale”, myxolydian mode, or the pentatonic. After playing for a while and letting each student experiment with improvisation the conversation could then move into harmony, tonality, and structure. We would then give labels to the concepts they already understood because they have played them. Listen to the changes for bass root movement and teach them a little about Roman numeral analysis, talk a little about myxolydian and modes in general, etc. The theoretical knowledge needs a framework in the student’s mind before we toss around labels, otherwise it is devoid of meaning for them.
The first point I have about theory is to let them experience before you explain. Both pieces are key but we put the cart before the horse far too often. The second is to remind them that the role of music theory is just that, a theory not a law. Most of us learned tonal harmony with the baggage of “rules”; VI goes to V, always resolve the 7th of a chord downward, write parallel fifths and you make Bach cry, etc. This prescriptive method serves to stifle creativity, it certainly stifled mine. I always liked the idea that going outside of the lines was acceptable as long as you knew where the line was.
A running theme through all of these thoughts: Let students play, in all senses of the word. Let them play their instruments and let that be playful. Guide, coach, and explain just make sure its in the right order!