Trombone Voicings

Four notes in the right hand, one in the left, and it sounds like a horn section.

What they are

A closed voicing is four chord tones inside one octave. Play one in your right hand and you get a section, four trombones or four saxophones on a single chord.

Twenties dance band piano uses it in the oom-pah, left hand on the bass note, right hand answering. James P. Johnson and Earl Hines paddle it, root on one beat and chord on the next, quarter after quarter through a chorus, and Teddy Wilson does the same behind a singer. Bebop uses the same shapes, and Tadd Dameron, Bud Powell, Al Haig, and Thelonious Monk stab them between phrases.

Where on the keyboard

The shape straddles middle C. Put it in the octave that holds middle C inside it. Middle C is never the top note of the shape, so a chord that would sit at or under it moves up an octave. A few shapes are too narrow to hold middle C inside, and those sit just above it.

The left hand takes the nearest root below the shape, but never closer than a minor third. If the nearest root crowds the shape, take the one an octave down. Drop another octave when you want weight. Keep it in a bass player's range, between the low E of a bass and the G below middle C.

Four notes packed around middle C sound dark and rich, and down there the shape stays under a soloist and adds weight.

Low roots

Method books tell you to stay out of the low register and to leave the root to the bass player. Both rules come from a later style of playing.

Listen to the records. Lil Hardin plays low roots on the beat through the 1923 Oliver sides. Teddy Wilson plays low roots and tenths on the Holiday dates. Bud Powell drops root and seventh into the bass register under his own lines, and Monk and Basie do the same. Red Garland comps with this exact shape behind Miles, right hand over a low left-hand root, with Paul Chambers underneath.

Doubling the bassist is fine as well. Piano and bass hitting the same root in the same octave is the sound those rhythm sections wanted, and it locks the time. Rootless voicings came in later, with a different kind of bass playing behind them.

The chord types

Seven shapes. Each is a root, a third, a fifth, and either a sixth or a seventh. The chord type tells you which of the four to lower.

Pick a root and a chord type below, and every lit key shows its place in the chord. Each change sounds as you make it. The arrow keys step through the inversions, and the labels follow the notes.

Inversions

Every shape has four inversions, one for each chord tone on the bottom. Learn all four in all twelve keys, until you can see a chord symbol and land on any of its shapes without thinking.

Voice leading

Move between the shapes without jumping. Take the inversion of the next chord nearest the one you are holding. Most notes move a step or stay put.

Let the top note fall. The ear follows the top voice, so a falling top gives the chords a line of their own. Take the closest inversion whose top note drops. Holding the top note is fine when nothing drops it. A rising top note sounds wrong here, so take one only when the register leaves no other choice.

Common progressions

The same rules run on the stock progressions. Pick a key and click a chord to hear it. The switch marked Major chords turns every 6 into a major 7. Each card also carries a variant menu and an inversion menu.

A close major 7 always holds a half step between the seventh and the root. In the middle of the shape it adds bite. On the top two notes it grates, so the voice leading keeps it off the top. Step onto that inversion and listen. That is why arrangers wrote the 6 chord instead.

The Song menu in the same widget swaps the stock progression for a whole tune, 50 standards from Autumn Leaves to Well You Needn't. The grid shows the form four bars to a row, and the menus under it act on the chord you have selected. Play all walks the form at the tempo.

Playing the ninth instead of the root

The left hand already has the root, so the right hand can drop its own and play the ninth. C6 becomes C6/9, D E G A over a C in the bass. The trade works on major 7, major 6, minor 6, dominant 7, and minor 7. Diminished 7 and minor 7 flat 5 shapes keep their root.

On a major 7 it is also the arrangers' fix for that clash. Cmaj9 is D E G B, and the half step is gone from every inversion. The Variant menu on any card has it as 9 for 1. Play the plain shape against the extended one.

Minor 7 chords come in three kinds, and the ninth is not equally welcome on each. The ii and the vi take it: Dm9 and Am9 in C sound like what they are. The iii does not. Em7 in C is the tonic chord without its root, E G B D against a C in the bass, and its natural ninth is F sharp, the sharp four of the key. Nobody plays that. Which is which depends on context rather than on the key signature, since a tune tonicizes as it goes, so the progressions widget reads the chord after each minor 7. A minor 7 that leads a 2-5 into a major chord is a ii and gets the 9 for 1, and a 2-5 that repeats a few times before it lands, as in Honeysuckle Rose, counts by where it lands. Em7 to A7 to Dm7 does not count, because that is a turnaround in C and the Em7 is still the tonic. Any other minor 7 keeps its root for now.

Altered dominants

A dominant that resolves down a fifth can be altered. Two stock ways use shapes you already know.

The alt chord: the minor 6 shape a half step above the root. For G7 going to C, play Abm6, Ab B Eb F, over a G in the bass. Those are the flat ninth, the third, the flat thirteenth, and the flat seventh of G7.

The b9 chord: the diminished 7 shape on the flat ninth. For G7, play Abdim7, Ab B D F, over a G.

Both shapes start a half step above the root. In root position that puts the nearest G a half step under the shape, so take the G an octave lower.

Any dominant that resolves down a fifth wants one of these. The progressions widget alters those chords on its own, choosing b9 or alt by the voice leading, and the Dominants switch turns that off if you want to hear the plain chord. A dominant that goes somewhere else, like the F7 back to C7 in a blues, stays plain.

How to practice

Play each progression in all twelve keys, around the circle of fourths. Start from a different inversion of the first chord each time, so you learn all four paths. Then drop the left hand an octave and listen to the weight change.