Roots, Keys and Applying Scales

As I teach in Fretboard Theory Chapter 7 (Roots, Keys and Applying Scales), you must identify the one major scale that the whole progression stems from in order to know what major scale to use for melody, riffs, and solos. But the pentatonic needs only to correspond to the root chord in a progression.

Major Scale Patterns
For example, the guitar solo in the acoustic version of "Layla" by Eric Clapton uses the chords Dm, Bb and C with Dm functioning as the root (where everything leads to and resolves). These three chords together can only fit into the F major scale. So you can play F major scale patterns over the whole progression.

Pentatonic Scale Patterns
Since Dm is the root chord, you can play Dm pentatonic over the whole progression as well. In fact, the pentatonic notes are all in the major scale. So the pentatonic is really just the major scale minus two intervals (in this case the 2nd and minor 6th). But guitar players visualize and play in pentatonic and major scale patterns differently. This is why we have names for the two and they're taught differently.

Clapton's approach to this solo section is a combination of both. Some of his phrases are based on full major scale patterns while others are in typical pentatonic boxes.

Music Theory For Guitar
Of course, there are more options to choosing scales for solos but what I've outlined above is what is generally done most of the time. Be sure that you completely understand this guitar theory and have mastered applying these concepts before you explore more complicated ideas.

Play Until Yer Fingers Bleed!
Mr. Desi Serna
Website: http://Guitar-Music-Theory.com
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Black Magic Woman Guitar Music Theory Lesson Video

This is a break down of the scales, modes, chords and progression used in the song "Black Magic Woman" by Santana. Played and taught by guitar theory teacher Desi Serna of http://Guitar-Music-Theory.com. Guitar tab and audio jam track are available in the book/CD pack Guitar Play-Along Volume 8 from Hal Leonard.

What is the "Key" of a song?

"Key" can refer to a several things. They include:

1. The key signature or parent major scale
2. The root
3. The first note or chord of a song.
4. The mode

In most cases when a guitar player says "key," he is referring to the chord or note that sounds like the tonal center of the song. This root may not always match the actual key which should be based on the parent major scale. For example, "Gloria" by Van Morrison revolves around, and resolves on E, but the chords are derived from the A major scale's V IV and I (this produces E mixolydian mode).

Sometimes guitar players will name a key simply by whatever note or chord is first. For example, "Sweet Home Alabama" by Lynyrd Skynyrd starts on D, but G is the strongest tonal center, and the chords are derived from the G major scale's V IV and I. The majority of the melodies, riffs and solos are based on G major pentatonic and G major scale. It's more correct to say the song is in G, but most players call it D.

As you can see, guitar players have different meanings for the word "key," and musicians can examine a song's structure from different perspectives. A good approach to learning guitar theory is to always start with the parent major scale, then identify which note is functioning as the root.

Play Until Yer Fingers Bleed!
Mr. Desi Serna (Google me!)
http://www.Guitar-Music-Theory.com
Scales, Chords, Progressions, and More