Cadd2 - A Piano Secret

The first four note chord is named Cμ or C mu. (μ is a Greek letter pronounced “m’yoo” ).   It’s more commonly called Cadd2, because it’s a C major chord with a D (the second in C major).  It’s sometimes called Cadd9 or CaddD.

Occasionally you see it written C9, which is ambiguous.  C9 is also the name for a different chord: c e g Bb d.  That’s how I learned to play C9.  That C9 is a dominant chord -- a C7 with the ninth (D) added.  If you want to be totally clear you can call it something like Cdom9 or C79, but it’s almost always written C9.  Sometimes you’re playing a chord progression that has a ninth chord written in it, like C9, but the chord doesn’t sound right.  In that case try it without the seventh, without the Bb, because perhaps the chord the writer was trying to convey was really Cadd2.  

Whatever you call them, add2 chords are one of the true secrets of piano your teacher never taught you.  (Cadd2 has been hiding behind C9 the whole time.) You can add the second to almost every major chord to positive effect.  Your friends will think you play much better once you start adding 2.

A typical way the mu chord is employed is to play it broken, letting the suspended second quickly resolve to the major.  I’ve heard this called the country third and the pentatonic twang though I don’t think those are very common terms.

Calling it the mu chord comes from Steely Dan, who employ it often to add color and interest to a major chord without giving it a sixth or seventh or other tone that would alter the flavor significantly.

It’s not just Steely Dan.  Elton John, Nicky Hopkins, Bruce Hornsby and Ben Folds all like to add the second to major chords.

While we’re here, I’ll mention the pentatonic turn, which is an obscure name for a common riff played with the add2 chord.  (It’s a bad name, because it’s somewhat similar to though not exactly the same as the musical ornament called the turn.)   I play it way too much.

The example that popped into my head is The Who’s The Song Is Over, which uses the turn, and a variation on it, as the last chord in the four chord verse progression.   That chord happens to be an F, so I wrote the turn here on F instead of the usual C I’ve been abusing.  As you can see, it’s the country third with an extra note, the root, added.  The variation plays the second then the root. 

You can also play a turn on a major sixth chord, and thus you can play pentatonic scale notes down the keyboard by alternating between the turns on F6 and Fadd2.  

Another well-known example of the pentatonic turn is the piano in the chorus of the Marshall Tucker Band’s Heard It In A Love Song (clip).


Next: Csus2 and Other Suspended Chords