John Proulx
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If you thought that you’ve heard of all the chord types out there, you might need to think again. In today’s lesson, The Mu Chord (Steely Dan Chord) for Piano, John Proulx shares how to play a beautiful chord with an unusual name. That’s right, it’s called the Mu Chord (pronounced like “Moo”) and its sophisticated sound is equally at home in rock, contemporary pop, new age, modern jazz, R&B and contemporary gospel music. You’ll learn:

If you enjoy discovering new harmonic possibilities or playing traditional tunes with a modern twist, then this lesson is for you!

Intro to the Mu Chord

If you’ve been playing piano for a while but you’ve never heard of the Mu Chord before, then you’re probably wondering, “How could there be another chord type out there?” Well, depending on your listening exposure, you may have already encountered the sound of the Mu Chord and perhaps even played it before on the piano, albeit by a different name.

The term “Mu chord” was coined by Donald Fagen (b. 1948) and Walter Becker (1950–2017), co-founders of the American rock band Steely Dan. They actually used the term Mu Major Chord—which others have shortened to Mu Chord—to refer to a major chord with an added 2nd. It quickly became one of Fagen and Becker’s favorite chords and is a defining characteristic of Steely Dan harmony.¹

“It was kind of a joke, that name. In the late ’60s when we first started writing together, we would write or play very simple tunes and the way that we came up with hopping up major triads was to add a 2nd, usually right under the 3rd. This was one of the few alterations that you could do to a major chord and still have it sound like a major chord and not a jazz chord.”

—Walter Becker, Steely Dan co-founder

Embed from Getty Images
Walter Becker (left) and Donald Fagen (right) in 1977.

In a 1989 interview with Metal Leg (a small Steely Dan fan magazine), Walter Becker further explained, “At that time the people in the rock audience, if they were aware they were hearing something that sounded like jazz, they weren’t too happy about it. This is something that Donald and I always had to struggle with, to incorporate some harmonic elements that were more sophisticated than rock and roll, and still have it sound like rock and roll.”²

Mu Major Chord: Origin of the Name

According to Becker, “I don’t remember why the name (laughs) ‘Mu chord.’ I’m sure there was some very important reason at the time.” Regardless of the name’s forgotten inspiration, it has stood the test of time.

A less-known fact is that Mu is the twelfth character of the Greek alphabet. An uppercase mu looks just like a Latin “M” However, a lowercase mu (μ) is used as a special symbol in many academic fields. In fact, some Steely Dan song books even use μ as a chord suffix to represent major chords with an added 2nd. For example, the sheet music would feature a chord symbol such as Cμ to represent a four-note chord containing the notes C–D–E–G, which is more commonly known as C(add2) or C(add9).

What is the difference between Sus2 and Add2 chords?

Since sus2 chords and add2 chords both depart from the familiar structure of basic triads (root–3rd–5th), many beginner students are unsure what to do with the 2nd when they see either chord symbol. Although sus2 chords and add2 chords are similar, they are not the same. Comparatively speaking, add2 chords sound brighter than sus2 chords (see examples below).

When you see the “sus” chord symbol, this is shorthand for suspended. Usually, the “sus” is followed by a number, such as sus2 or sus4. However, when there is not a number present in the chord suffix, then sus4 is assumed. In a suspension, the 3rd of the chord is replaced by an adjacent note—either the 4th or the 2nd. Therefore, C(sus2) is a three-note chord containing the notes C–D–G. Remember, the 2nd (the note D) replaces the 3rd (the note E).

On the other hand, when you see an “add” chord suffix, this indicates that you are dealing with a triad plus an added color note. The most common type of add chord is an add2, which can also be called an add9. Therefore, C(add2) is a C major triad with an added 2nd: C–D–E–G.

Sus2 Chord

What is a sus2 chord?

Add2 Chord

What is an add2 chord?

As we have defined it thus far, the Mu Major Chord (or μ major) is technically equivalent to an add2 chord. However, as we further examine its usage, we’ll discover that usually the term Mu Chord refers to some specific ways of voicings add2 chords.

How to Construct Mu Major Chords

The essential notes of a Mu Major Chord are the root, 2nd, 3rd and 5th (R–2–3–5). However, in the same interview cited previously, Walter Becker indicates that in songwriting for Steely Dan, they preferred to voice the 2nd directly below the 3rd so as to create a whole tone cluster. Therefore, of the following C(add2) voicings, the examples that are most associated with the Mu Major sound are those in measures 1, 2 and 4, which contain a whole tone cluster.

Cadd2 / C Mu Major Piano Chords

How to Construct Mu Major Chords

Modern Mu Chord Voicings

By the time that Fagen and Becker were writing for their fifth Steely Dan studio album, Royal Scam (1976), and on subsequent albums, they developed another way of voicing Mu Major chords—in first inversion.  Placing a Mu Major Chord in first inversion gives it a distinctly different character that sounds more modern and jazzy. Guitarist Howard Wright, who has written appreciably on the Mu Major Chord, describes this as a Type Ⅱ voicing.³ In fact, if you hear another musician refer to a Mu Chord nowadays, it is likely this quintessential sound to which they are referring. (By contrast, Harold Wright refers to root position Mu Major chords as Type Ⅰ voicings.)

All Type Ⅱ Mu Major Chords feature the 3rd of the chord in the bass. However, the right-hand notes can be inverted into 3 possible shapes. Of these possibilities, quartal shapes (shape 1 below) and inner cluster shapes (shape 2 below) are much more common than upper cluster shapes (shape 3 below).

Modern Mu Chords – Cadd2/E

Modern Mu Chord Voicings

Let’s briefly examine the shape 1 quartal voicing in the example above: E–D–G–C. It is quartal in the sense that the right hand plays two perfect 4th intervals (D–G–C). However, the interval from the bass note E up to the D in the thumb of the right hand is a minor 7th. Moreover, this voicing also contains a G. Taken together, those three pitches, E–D–G, strongly suggest some sort of Em7 voicing. However, the C in the uppermost voice is a bit peculiar for an Em7 chord. Nevertheless, you will sometimes find the chord symbol Em7(♯5) for this chord. That withstanding, C(add2)/E is the more mainstream choice when naming this chord.

Song Examples with Mu Major Chords

Examples of Mu Major chords can be heard in the intros to the Steely Dan songs “Reelin’ in the Years” (1972, Type Ⅰ) and “Deacon Blues” (1977, Type Ⅱ). In fact, Mu Major chords appear on all nine Steely Dan studio albums.

Younger generations of students who are less familiar with Steely Dan and their music might be inclined to wonder whether or not it’s truly important to know “The Steely Dan Chord.” Admittedly, the harmonic potential is much more important than what you call it. As it turns out, this chord comes up a lot in contemporary music. For example, the Type Ⅱ voicing can be heard several times right away in the opening of “Win” (2000) by Brian McKnight. Likewise, Type Ⅱ voicings are also featured prominently in “Take My Life (Holiness)” (2004) by Micah Stampley.

🔎 For a deep dive on how to use Type Ⅱ Mu Major chords in contemporary gospel piano music, check out our Gospel Soul (Adv) course.

Mu Chord Practice Exercises for Piano

In this section, we’ll explore some practice exercises that will help you become more familiar with the sounds and hand shapes for the Mu Chord. Then, in the final section, we’ll demonstrate how to apply these beautiful voicings to the popular song “Amazing Grace.”

Parallel 10ths Exercise

Our first exercise is an ascending C major scale in parallel 10ths. Just in case you are unfamiliar with compound intervals, a 10th interval is equivalent to a 3rd plus an octave. In this example, the Ⅰ, Ⅳ and Ⅴ chords are Mu Major Type Ⅰ voicings. However, when the note E is in the bass, we use a C(add2)/E Type Ⅱ voicing. Similarly, when the note B is in the bass, we use a G(add2)/B Type Ⅱ voicing. (Note: The * designates minor add2 chords, which are constructed R–2–♭3–5.)

C Major Scale Parallel 10ths with Add2 Chords

Major Scale Parallel 10ths with Add2 Chords

Planing Exercises

Next, we’ll explore four different planing exercises. The term planing refers to the exact transposition of a voicing to a different pitch level. Another term for planing is parallelism. Some examples of planing would be to move a voicing up or down chromatically, in whole steps, or in major or minor 3rds.

The first planing exercise below places a C major scale in the upper voice and harmonizes it with Mu chords using the Type Ⅱ quartal shape. Since each melody note is the root of a Mu Major Chord, this results in several chords that are not native to C major. However, you’ll notice that they are all common secondary dominants in C major. For example D(add2)/F♯ is the Ⅴ of Ⅴ. Likewise, E(add2)/G♯ is the Ⅴ of Ⅵ. Therefore, this exercise can help you discover new ways to incorporate secondary dominants into your playing with a more contemporary sound.

C Major Scale (R.H.) with Mu Chords – Shape 1

C Major Scale (R.H.) with Mu Chords - Shape 1

The next planing exercise is similar to the previous exercise in that it harmonizes a C major scale in the upper voice with Mu chords. However, this exercise uses Type Ⅱ inner cluster shapes. Notice, each melody note is now the 5th of a Mu Major Chord. As a result, the harmony has changed. In fact, we even get a borrowed chordthe ♭Ⅶ, when F is in the melody.

C Major Scale (R.H.) with Mu Chords – Shape 2

C Major Scale (R.H.) with Mu Chords - Shape 2

Now, let’s take the opposite approach. We’re still thinking in the key C major, only now we’ll place the ascending C major scale in the left hand. This means that each note of the C major scale will now be the 3rd of a Type Ⅱ Mu Major Chord. Surprisingly, this gives us a completely different set of chords.

The first example below uses Type Ⅱ quartal shapes. In this particular key, the first two voicings are a bit muddy. However, this example demonstrates that we can use Mu Chords over a diatonic bass line to introduce borrowed chords from the parallel minor, such as the ♭Ⅱ, ♭Ⅲ, ♭Ⅵ and ♭Ⅶ.

C Major Scale (L.H.) with Mu Chords – Shape 1

C Major Scale (L.H.) with Mu Chords - Shape 1

Next, we’ll keep the ascending C major scale in the bass line, but now we’ll build Type Ⅱ Mu chords above it using the inner cluster shape. Since the bass line still features the 3rd of each chord, we wind up with the same chord progression as in the previous example. However, now we have a different melodic line in the right hand.

C Major Scale (L.H.) with Mu Chords – Shape 2

C Major Scale (L.H.) with Mu Chords - Shape 2

Application: Using Mu Chords in a Song

In the final section of today’s lesson, we’ll listen to John Proulx’s arrangement of “Amazing Grace,” which intentionally highlights the Mu Chord sound. Notice how these extensive add2 chords give this arrangement a bright and contemporary character. In fact, this arrangement is included in today’s lesson sheet PDF. In addition, this lesson also includes a backing track. These downloadable resources appear at the bottom of this page after logging in with your membership. PWJ members can also easily transpose the lesson sheet examples to any key using our Smart Sheet Music.

Amazing Grace with Modern Piano Chords


Congratulations, you’ve completed today’s lesson on The Mu Chord (Steely Dan Chord) for Piano. In the process, you’ve expanded your musical vocabulary to include one of the most versatile modern harmonic sounds!

If you enjoyed this lesson, then you’ll love the following PWJ resources:


Thanks for learning with us today! We’ll see you next time.



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¹ Wright, Howard. “Steely Dan: The MU Major Chord – Part 1.” Hakwright.Co.Uk, Feb. 2017.

² Zollo, Paul. “Winter 1989 Interview with Walter Becker.” Metal Leg, Issue 14, Fall 1990.

³ Wright, Howard. “Steely Dan: The MU Major Chord – Part 2.” Hakwright.Co.Uk, Feb. 2017.

Michael LaDisa

Michael LaDisa graduated from the University of North Texas with a major in Music Theory & Composition. He lives in Chicago where he operates a private teaching studio and performs regularly as a solo pianist. His educational work with students has been featured on WGN-TV Evening News, Fox 32 Good Day,...

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