Common Chord Modulation: Diatonic Pivot Chords

Many of the standard expression tools used on most instruments aren’t available to hammer dulcimer players.  We can’t do vibrato.  Bending notes can be done but can be difficult to fit into a fast melody, and it often knocks an instrument out of tune.  We can’t control sustain.  We can’t crescendo on a tone.

But we can change the key in which a melody is played.  That act is called modulation.  It’s an effective technique on the hammer dulcimer; especially for solo players.  Here’s  how to do it.

The “bad news” is that you’ll have to learn the tune in two or more keys. Changing keys on the hammer dulcimer isn’t all that difficult.  The hammering patterns are very similar from one key to another.  The big differences are where to begin playing and where to cross the bridge.  Give a thought to the accomplished jazz player.  When that level of musician says “I learned the tune ZZZZZ”, the implied meaning is that the player has mastered the tune in all twelve chromatic keys.  That’s no small feat!  Dulcimer players should be able to manage two or three keys without fussing!

Pivot Chord Defined.
A pivot chord is a chord that is present in two keys.  We’ll stay with the diatonic scale since that is what most dulcimer music uses.  That’s the familiar do re me fa so la ti do scale.

The chords constructed on the diatonic G scale are:

     G    Am    Bm    C    D    Em    F#º    and   G

The chords constructed on the diatonic D scale are:

       D  Em  F#m  G   A   Bm  C#dim  and D

See the pattern?  No matter what the scale or key, the pattern of the chords is always the same on the diatonic scale

     I    ii    iii   IV     V     vi    viiº

The scales of G and D share these chords:

     Bm, D, Em, G

Using Pivot Chords
These chords are the pivot chords between the keys of G and D.  So when you arrange a tune such that the key will change from, say G to D, one or more of these four chords will help make the transition smooth and ensure the change isn’t abrupt.

The most frequently used pivot chords are the ii and IV chords of the new key.  Again, if the movement is from the key of G to the key of D,  those chords are Em and G.  Don’t overlook the Bm as a pivot chord.  It isn’t used as much and that can make it particularly effective. 

The other point about using pivot chords as the transition for a modulation is that you are not limited to a single chord.  It is possible to establish a bit of harmonic rhythm by employing several of the pivot chords in sequence. 

The Theory
Chords on a diatonic G Scale:  I     ii    iii  IV   V   vi   viiº

Equivalent chords from the
Diatonic D scale:          IV   V   vi  viiº   I   ii    iii

Pivot chords are any chords with the same naming tone (root tone) and quality (major, minor, diminished).  

So, moving from the scale of G to the scale of D, the pivot chords are:

     G   (I in G but IV in D – both major chords)

     D  (V in G but I in D – both major chords)
     Em (vi in G but ii in D – both minor chords)

     Bm (iii in G but vi in D – both minor chords)

These four chords – Bm,  D,  Em, and G – are the pivots you can use to modulate between the keys of G and D.