I’ve been asked many times “Why do I need to learn and practice scales?” or “Why do I need to understand chords-scales and tonal harmony?”
Some other people complain about the chord-scale theory, saying that they don’t want to play scales, meaning they wish to play in the jazz vocabulary, licks, motives, playing rhythmically or maybe playing by ear. Non of these contradict the use of the chord scale information. It doesn’t even contradict playing “out”! It merely informs the ear and clarifies how certain tones will work over a chord. The chord-scale information shows the collection of chord-tones and tensions in between them in the key of the moment. That’s it. What you do with that information is up to you. Whether you want to play inside the key with this notes, or “rub” against the chord changes, will depend on your artistic choice, in the moment.
In a harmonic progression, we usually find chord-scales that are the same collection of notes, from different starting points. Let’s examine an example:
IImin7 (Dorian) – V7 (Mixolydian) – Imaj7 (Ionian) in the key of C:They are the same seven notes! It’s just the c major scale using different notes as starting points. So what’s the difference? The difference is which notes are chord-tones or tensions over each chord. They will have a different sound and different tendencies over each chord.
The main idea I’d like to convey in this post it that we don’t need to play all the notes in a scale nor do we need to play scale-wise. Having the chord-scale helps us understand which notes work tonally over a chord. For instance in this simple IImin7-V7-Imaj7 progression we use notes inside the chord scales:Another approach is finding just a couple of notes that are common to several chord-scales and using them as a motive across a chord progression. Here’s an example of a two-note motive across several chords:Here’s another important benefit from understating the chord-scales in a progression: We can simply stay faithful to any musical idea by keeping it’s rhythm and contour and just adapting the notes according to each chord-scale:Let’s see two more examples of using just a few notes out of the scale to create an iconic phrase in the jazz language. Every note in this phrase belongs to the altered scale, but not all the notes in the scale are used:If we take all of this a step further, we can find upper structures inside a scale like upper structure triads or other structures. For instance we can find a minor pentatonic scale inside an altered scale:Now that we identified C minor pentatonic inside A altered, we can use as an upper structure. Here you can see C minor Pent over A7alt in the first measure:There is so much to say about this topic that it could be an entire book by itself, but I will close this post with one more concept: Knowing the chord-scale gives us the target notes for any kind of chromatic or diatonic approach and passing tones:I hope this helps to clarify the value of understanding tonal harmony, harmonic functions and chord-scale information. A partial understanding of these concepts might lead to believe that we are supposed to play only the notes in the chord scale, all the notes in the chord scale, or playing scale-wise. Nothing further from the truth. Harmonic functions and chord-scale information provide us the building blocks to create melodies, riffs, motives, etc. They are just starting point, a trampoline for our creativity.
Written by Mario Cerra at mDecks Music.