Movable 7th Chords on Middle Strings

Welcome to your first lesson. We're kicking off your journey to master the modern guitar style of bands like Polyphia by building a strong harmonic foundation. Their music, while technically dazzling, is built on a sophisticated understanding of chords and harmony. This module will equip you with that vocabulary.

Today, we'll focus on constructing movable voicings for the three most fundamental 7th chords—major 7th, minor 7th, and dominant 7th. We'll specifically target the middle four strings of the guitar, which gives us a versatile and clear harmonic range. You'll learn not just what shapes to play, but how they are constructed. This is a much more powerful approach than rote memorization, allowing you to "generate" chords on the fly, a skill essential for navigating the fretboard with the freedom you're aiming for.

From Simple Chords to Rich Voicings

You're likely familiar with basic major and minor chords, often played in open position. To get the richer sounds of modern guitar, we need to move beyond these and into the world of voicings. A voicing is simply a specific arrangement of the notes of a chord. Different voicings of the same chord can have dramatically different sounds and textures.

The specific type of voicing we'll learn today is called a Drop 2 voicing. It's a cornerstone of jazz harmony and has been adopted by countless modern players for its playability and balanced sound.

Let's start by understanding the theory behind them.

The basic algorithm is simple:

1. Start with a 7th chord stacked in order (a "closed voicing"), for example, Cmaj7: C-E-G-B (Root - 3rd - 5th - 7th).
2. Identify the second-highest note. In our Cmaj7, that's the 5th (G).
3. "Drop" that note down an octave.

The resulting note order for our Cmaj7 becomes G-C-E-B. This spread-out structure, or "open voicing," sits beautifully on four adjacent guitar strings.

For a video walkthrough of this concept, the following video offers a clear, quick summary.

Focusing on the Middle Strings

Our learning outcome specifies using the "middle four strings." On a standard-tuned 6-string guitar, this refers to strings 4, 3, 2, and 1 (D-G-B-E) or 5, 4, 3, and 2 (A-D-G-B). We will focus on the 5-4-3-2 string set, as it offers a great tonal balance.

A quick note on your 7-string and Drop F tuning (F-C-F-A#-D#-G-C): the principles of chord construction are universal. A major 7th chord is always made of the root, major 3rd, perfect 5th, and major 7th, regardless of tuning. However, the fingerings—the shapes—will change with the tuning. For these foundational lessons, we'll use standard tuning as our reference, as it's the basis for most instructional material. The shapes you learn here are directly transferable to a standard-tuned 7-string. Later in the course, we'll specifically tackle how to adapt these ideas to alternate tunings.

The article below explains why different string sets have different characters and why the middle set is a good choice.

The Voicings: Major 7th, Dominant 7th, and Minor 7th

Now, let's get the shapes under our fingers. We will treat the Major 7th (Maj7) chord as our "base" pattern. Once you know the Maj7 shapes, you can derive the Dominant 7th (7) and Minor 7th (m7) shapes by altering just one or two notes—a simple, systematic process.

A chord can be played in different inversions. An inversion just refers to which chord tone is in the bass (the lowest-sounding note).

• Root Position: Root is in the bass.
• 1st Inversion: 3rd is in the bass.
• 2nd Inversion: 5th is in the bass.
• 3rd Inversion: 7th is in the bass.

This gives us four distinct, movable shapes for each chord quality. Let's start with the Major 7th.

1. Major 7th (Maj7) Voicings

First, let's look at the chord diagrams for all four inversions of a Major 7th Drop 2 chord on the middle string set. The root note is marked with an 'R', which is your anchor point for moving these shapes around the neck.

Now, watch how these shapes are played and get some crucial advice on fingering from a master instructor, Tomo Fujita. The way the guitar is tuned requires different shapes on different string sets, and some of these new shapes can feel like a stretch.

2. Dominant 7th (7) Voicings

To transform any Major 7th voicing into a Dominant 7th, you only need to make one change: lower the 7th by one semitone (one fret). The interval formula changes from R-3-5-7 to R-3-5-♭7.

Let's look at the diagrams for the Dominant 7th shapes.

Now, let's see these in action.

3. Minor 7th (m7) Voicings

To get a Minor 7th chord, we alter the Major 7th chord in two places: lower the 3rd and the 7th by one semitone each. The formula becomes R-♭3-5-♭7.

Again, let's consult our reference diagrams.

These voicings also have some memorable characteristics that can help with recall.

Application: Making the Shapes Movable

The power of these shapes lies in their movability. Because they don't use any open strings, you can slide them to any position on the neck to play a chord of the same quality in a different key. The key is to always know where the root is in each shape. The diagrams from Jazz Guitar Guide are perfect for this, as they label the root note 'R'.

Your task:

1. Pick one voicing, for example, the root position Major 7th shape. The diagrams show this as a Cmaj7 with the root on the 8th fret of the 5th string (A string).
2. Play that Cmaj7 chord.
3. Now, move that entire shape up two frets, so the root is on the 10th fret of the 5th string. This note is D. You are now playing a Dmaj7 chord.
4. Move the shape down five frets from there, so the root is on the 5th fret of the 5th string. This note is G. You are now playing a Gmaj7 chord.
5. Repeat this process with one Dominant 7th shape and one Minor 7th shape. For example, use the "Mr. Spock" Minor 7th voicing (1st inversion) and move it to a few different positions.

This exercise solidifies the connection between the shape, the root note, and the resulting chord. The instructor in the video from Juan Antonio Music actually points out that one of these Minor 7th voicings sounds a lot like a chord used in a Polyphia song. This is a great example of how these "jazzy" voicings are fundamental to the modern sound you're chasing.

Conclusion

In this lesson, you've taken a significant first step into a more sophisticated harmonic world. You've learned how to construct and play movable Drop 2 voicings for major 7th, minor 7th, and dominant 7th chords on the middle four strings.

Key Takeaways:

• Voicings are specific arrangements of chord tones that create unique textures.
• Drop 2 voicings are created by dropping the second-highest note of a closed 7th chord by an octave, making them highly playable on guitar.
• By learning the four inversions of a Major 7th chord, you can systematically derive the corresponding Dominant 7th (by flatting the 7th) and Minor 7th (by flatting the 3rd and 7th) shapes.
• The key to making these shapes movable is to identify the root note in each voicing and use it as your anchor on the fretboard.

In our next lesson, we will build directly on this foundation. We'll take these 7th chords and learn how to construct and voice even richer harmonies: 9th, 11th, and 13th chords. These "extensions" are what give modern guitar harmony its color and complexity.