Piano To Guitar And Back Again

A friendly guide to learning guitar shapes and where they exist on a piano. We’ll also take ideas from piano and convert them to guitar.

The Conversion Problem

I found myself at a disadvantage when I had the opportunity to take a college music theory class. I was playing guitar, but the instructor was teaching music theory using a piano. These days I use a piano to teach as well because the piano has the advantage of being played solely by intervals. The guitar also has its own advantages, which are moveable shapes. You can hold chords on the neck of the guitar and move that "shape" along the fretboard. Doing so gives you different notes, but the chord is the same. Here are some examples that I made using the resources at https://chordpic.com/. Each row starts with the intervals used to make that chord, which is then followed by two examples with notes.

Guitarists tend to move their fretting hand based on “moveable shapes” because they always give you the same interval structure. That is how we will be able to convert chords to and from the piano. Looking at the same Maj7 chords with the same notes on a piano gives us a different “shape”. These piano chords may look completely different but look at the intervals. They are the same.

These two chords are the same intervals, but are rooted in two different notes: G and A.

When someone plays a chord like GMaj7 on a piano they are usually playing it in a simpler form than the one shown above. Here are two more examples of GMaj7 on piano.

These two chords have the same names because the have the same root note of G and the same intervals that follow the root. They are different “voices” because the use different pitches for the third and major seventh intervals.

These voicings of the same chord make more sense because you can easily get your hand over these notes on a piano. What is difficult to do, is to convert these exact piano chords into guitar chords. Below are three charts. The first two use the exact same notes/pitches as the G Maj7 piano chords shown above. Notice how the first chart (G Maj7 Piano 1) has two notes on one string. This chord is impossible to play because you can only have one note played at a time on a string. The next chart (G Maj7 Piano 2) can be played on the guitar, but you must deaden or mute two strings. The third chart shows a G Maj7 chord that can be played on guitar that matches the notes used on the piano and only adds notes that are already part of the chord.

Intervals Are Everything

Looking at a D Major triad on piano we have the notes D, F#, and A. Just like the other examples for piano, you can play these three notes in any order as long as D is the root note or lowest pitch. On a guitar we have three main shapes that are all D Major triads. Each shape has D as the root note and contains F# as the major third and A as the perfect fifth. The root note for each example shown below is also the same pitch. This means that they are all rooted in the same octave. Keep in mind that the two bar chords would have your first finger going across the top fret, or using your finger as a bar, to play those notes.

The goal with this is to be able to look at a piano chord and fit it to the guitar. We just need the intervals and root note so that our guitar can use the same octave as the piano. This way we won’t play our notes too low or too high. The addition or subtraction of notes, like in the three D chords shown above, is only due to the way the guitar is physically played.

Adjusting Guitar Intervals

Adjusting intervals on a piano is fairly easy if you know your chromatic scale. This scale uses all of the intervals, so you can quickly pick out the components of any chord, scale, or mode. If you want to know more about the chromatic scale, then check out my post the Two-Octave Chromatic Scale.

Let’s try creating guitar chords based on intervals. We’ll start with a D major triad and by adjusting one interval at a time we can create other types of major chords relative to the D major chord. Watch for the first and third degrees to remain the same so that we always have a type of major chord. Also, the root note of D will not be listed on the open string so that we can get used to knowing that the fourth string is already tuned to D. If you are not used to playing guitar, then just know that the strings are tuned to E, A, D, G, B, E from left to right and the lowest pitch is to the far right of any chord diagrams.

These are just a few examples of chords that use the first, major third, and perfect fifth. All we did was take the extra first degree note and moved it around. I did include one chord with a b5 because it is still a major chord due to having a major third degree interval. This chord is commonly used in the Lydian mode and is worth knowing due to its tension, which is created by the Tri-Tone interval between the root note and the b5 note.

So, what about minor chords? We can do the same thing. Watch for the root note and b3 note to remain, while the other notes change by just one interval at a time when compared to the Dm chord.

I added the Dm7 b5 chord because it is a chord from the Locrian mode that is easy to play. This is also a moveable shape. You can take these four positions on the fretboard and move the m7 b5 shape to any position and all you need to do is focus on the root note. Want an Ebm7 b5? Move the whole shape along the fretboard by half a step. That’s it. The best part with any shape is that they can be moved in the same manner. Try taking any chord shape that works for you and move it while keeping the root note in mind. You’ll find that you can play the same chords in multiple ways.

Take the various shapes of the major and minor chords and change one interval at a time. You may be surprised as to how many chords you can play by making small adjustments.

Guitar Back to Piano

So how do we use all these shapes for piano? A great place to start is by using the root and fifth degree. Most chords you use will have these intervals and they are easily found on the white keys of a piano by placing your thumb and fingers over a set of neighboring keys. Your thumb or pinky finger will be over either the root or fifth, depending on which hand you use. The only exception is the B diminished. This chord has a b5, which is perfect for building diminished chords like the half-diminished chord (m7 b5) or the fully diminished chord (m b5 bb7).

With those two points known on the piano, you can then play intervals that match any of the guitar chords shown in this posting. Want to play a D bar chord on piano? Then play degrees 1, 3, and 5 starting on D. How about something really cool like Bm7 b13/E as a Phrygian chord? This is a Bm7 chord with the fifth degree sharpened. Then play E as a root note below B. It looks like this.

The b13 is actually a b6 relative to the note B, but we can treat it as a b13 because E is acting as our root note. The note G is in the second ocatve of this chord relative to E.

I’ve included Em9 (11) because it is the exact same chord, but we treat E as the root note. This is a great Aeolian chord as well because it fits both modes. In fact, any chord will fit any mode, but they will use different intervals based on the root note used.

Without getting into a lot of modal intervals, know that any of the chords you use on any instrument with overlap with other chords. One such chord is the D major chord. Look at the diagram for that chord and compare it to Bm7 b13/E and you’ll see that three of the same notes are used in both chords. This means that you can play a D major chord and by adding a chord of E, B, G in the bass you can have an Aeolian or Phrygian chord. It all depends on the context or how you use it. Try playing E, B, and G in different orders so that each note can take turns being the root note. As you do, play the D major triad of D, F#, and A above that. As you do listen for the sound to change and look for how they overlap.

The point I’m trying to make is that you can use either instument and overlapping chords to find the sound you want. You can do this by ear, but pay attention to the intervals used. The intervals will always help you to gain access to the sound that you want and can help you to manipulate your chords to your benefit.

Using The First Ocatve

With everything we’ve covered in mind you should be aware of the first octave. Feel free to use any notes that match the intervals of your chord, scale, or mode. Just keep in mind that once you go past the first octave the even numbered intervals obtain a new function. This new function is treated as an extension of stacking major or minor thirds. If you want to learn more about octaves, stacking thirds, or degree functions then check out my post about the Two-Octave Chromatic Scale.

Thanks for reading Music Theory for Everyone! I really hope you enjoy these posts and find them useful. Please subscribe to receive new posts and support my work. You can also donate to this subscription if you would like to support it. Thank you.