What is an Alberti bass? How to play it on piano

After this lesson you can play an Alberti bass in the left hand on C, F and G chords while the right hand sings.

Listen to almost any easy piano sonata from the late 1700s and you will hear the left hand rocking gently back and forth under the tune, in an even stream of short notes. That rocking pattern is called an Alberti bass. It is one of the most recognisable sounds of the Classical style, and it is the main left-hand skill you need for the sonatinas that many pianists learn next.

The pattern is named after Domenico Alberti, an Italian composer of the early eighteenth century who used it so often that it became associated with him. Mozart's well-known Sonata in C major, K. 545, opens with a right-hand tune over exactly this kind of left hand.

What the pattern is

You already know how to play a triad, such as the C chord C E G, and how to break it into single notes. An Alberti bass is a particular way of breaking a chord, always in the same order:

lowest, highest, middle, highest.

For a C chord with C, E and G, that gives C, G, E, G. Then the pattern repeats: C, G, E, G, C, G, E, G. Played as eighth notes, two per beat, it makes a smooth, rocking wave.

One bar of Alberti bass on a C chord: C, G, E, G twice, with left-hand fingers 5, 1, 3, 1 below the notes

Fingering and hand shape

Because you are breaking one chord, the hand stays in one position for each chord. For the left hand on the C chord:

finger 5 on C (the lowest note),
finger 3 on E (the middle note),
finger 1, the thumb, on G (the highest note).

So the finger pattern is 5, 1, 3, 1, over and over. The thumb plays every other note, which is why it must stay light. If it thumps, the whole pattern sounds bumpy.

Left-hand C chord shape for the Alberti bass: finger 5 on C, 3 on E, thumb on G

Keep the hand gently curved over all three keys, with the fingers resting on the surface. The movement comes from a small rocking of the wrist and forearm, side to side, rather than from lifting each finger high. Think of a rocking cradle, or a slow ripple.

Changing chords: C, F and G

Most simple tunes use three chords, the ones you already know: C, F and G. The Alberti pattern stays the same on each; only the hand position changes.

C chord: C, G, E, G
F chord: F, C, A, C (with F below middle C, and middle C on top)
G chord: G, D, B, D (with G below middle C, and the D above middle C on top)

Alberti bass on C, F and G, one group per chord, then home to C. Shown in 2/4 to keep it short; the pattern stays the same on every chord

Notice that the F and G chords reach above the bass staff: middle C sits on a ledger line, and D just above it. The fingering is still 5, 1, 3, 1 for each.

The move between chords is the tricky part. Practise just the change: the last note of one group, then the first note of the next. Move the whole hand in one smooth shift, finger 5 landing on the new bottom note.

The right hand on top

An Alberti bass exists to support a tune, so the right hand is usually doing something simple and singing above it. In the Academy's Alberti Study, the right hand plays slow half notes while the left keeps rocking.

Alberti Study, bars 1 to 4, right hand: slow singing half notes above the C chord, then the F chord

Because the right hand moves so slowly, the challenge is to keep the left hand even underneath without the tune being swamped. The left hand should be quieter than the right, a steady background.

How to practise the Alberti bass

Hold the chord first. Play C, E and G together with 5, 3 and 1. Feel the shape. Then let go and keep the hand in that position.
Slow and even. Play C, G, E, G four times at a slow speed, counting "1 and 2 and". Every note should be the same length and volume.
Light thumb. Play the pattern again and listen only to the Gs. Are they softer than the other notes? They should be.
One chord per bar. Play two groups on C, then two on F, two on G and two on C, as a four-bar exercise.
Practise the changes alone. C to F, F to G, G to C. Shift the hand without a gap.
Add the right hand only when the left hand is completely steady, very slowly at first.

Common mistakes

Uneven rhythm. Often the first note of each group is long and the rest rushed. Count the eighths steadily.
Stiff wrist. Pressing each finger separately from a rigid hand is tiring and sounds jerky. Let the wrist rock.
Left hand too loud. It is an accompaniment. The tune should always be heard clearly above it.
Gaps when the chord changes. Plan the shift during the last note of the previous group.

Try it in Pianuvo

The Academy lesson demonstrates the rocking pattern, then has you play it on C, F and G and use it in the Alberti Study with both hands. Each exercise listens as you play and checks that the eighth notes stay even, whether you use the on-screen keys, a MIDI keyboard or a real piano through the microphone. It begins Unit 9: Toward the sonatina, and Year 1 review. When you are ready to hear a master use it, look at Mozart's Sonata Facile.