How to play the C major scale on piano with the thumb under

After this lesson you can play the C major scale with the right and left hand, passing the thumb under.

A scale is simply the notes of a key, played one after another in order. The C major scale uses only white keys: C D E F G A B C. It is usually the first scale anyone learns, and for good reason. It shows you the pattern that makes music sound "major", and it teaches a hand movement you will use for the rest of your playing life: passing the thumb under the hand.

The pattern of whole and half steps

You already know that a half step is the move to the very next key and a whole step skips one key. Walk up the white keys from C and measure each move:

C to D, D to E: whole steps
E to F: a half step (no black key between them)
F to G, G to A, A to B: whole steps
B to C: a half step

So the pattern is whole, whole, half, whole, whole, whole, half. Every major scale follows this pattern, whichever note it starts on. That is why the C major scale sounds bright and finished when you land on the top C.

The C major scale: all white keys, with half steps from E to F and from B to C

Five fingers, eight notes

Here is the problem. A scale has eight notes and you have five fingers. If you play C to G with fingers 1 to 5 you run out of fingers with three notes still to go. Jumping the whole hand along would make a bump in the sound.

The answer is the thumb under. In the right hand going up, play C, D and E with fingers 1, 2 and 3. While finger 3 holds E, the thumb slides quietly underneath the hand and lands on F. Now the hand is in a new place, and fingers 2, 3, 4 and 5 play G, A, B and C.

Right-hand fingering going up: 1 2 3, thumb under to F, then 1 2 3 4 5

Coming down, the movement reverses. Play C, B, A, G and F with fingers 5, 4, 3, 2 and 1. While the thumb holds F, finger 3 crosses over the thumb to land on E, and you finish with 3, 2, 1 on E, D, C.

Written out on the staff, with the finger number under each note, the whole scale looks like this.

The C major scale up and down for the right hand, with finger numbers below the notes

The left hand

The left hand uses the same idea, mirrored. Start with finger 5 on the C below middle C. Going up, play 5, 4, 3, 2, 1 on C, D, E, F, G. Then finger 3 crosses over the thumb onto A, and 2 and 1 finish on B and C. Coming down, 1, 2, 3 play C, B, A, then the thumb tucks under onto G and you continue 1, 2, 3, 4, 5 down to C.

So the left hand crosses over going up and passes the thumb under coming down: the opposite of the right hand. If you find that confusing, hold on to two simple facts: in the left hand the thumb plays G and C, and the finger that crosses over the thumb is always 3.

Going further: up to G5

Once the thumb movement feels natural, you can carry the scale past the top C. In the right hand, after B with finger 4, pass the thumb under again onto C, then play D and E with 2 and 3. Pass the thumb under once more to F, and finish on G with finger 2. That top G is G5, the note in the space just above the top line of the treble staff.

Continuing the scale above the staff: G5 sits in the space just above the top line

A step-by-step way to practise

Scales improve with short, regular practice far more than with one long session. Five minutes a day is plenty.

Thumb on its own. Rest the right hand in C position. Hold finger 3 down on E and slide the thumb under to touch F, then back to C. Do this ten times, slowly, keeping the wrist level.
Three-note groups. Play C D E F with 1 2 3 1 and stop. Then play F E D C with 1 3 2 1. Repeat until the join between E and F sounds as smooth as the other notes.
The full scale, very slowly. Play up and down at a speed where you never have to stop and think. Say the finger numbers aloud.
Count four per bar. Use a steady quarter-note beat, as in the staff above, with a half note on the last C.
Left hand separately. Practise it on its own in the same stages. Do not try hands together yet.
Listen. Record a few scales and listen back. Every note should be the same volume and the same length.

Common mistakes

Twisting the wrist or lifting the elbow to get the thumb under. The movement comes from the thumb itself; the hand and arm simply glide sideways.
A bump on F. If F sounds louder or late, the thumb is arriving at the last moment. Practise the three-note groups again.
Wrong finger on the top note. In the right hand, the top C of one octave is finger 5. If you reach it with 4, the thumb went under too late or too early.
Rushing the easy part. Many players speed up on the five-finger part and slow down at the crossing. Keep the beat even all the way through.

Try it in Pianuvo

The Academy lesson has scored scale exercises for each hand that listen as you play, on the on-screen keys, a MIDI keyboard or an acoustic piano through your microphone, then puts the scale to work in Aura Lee. It is part of Unit 5: Sharps, scales and G major. For more on finger numbering, see piano finger numbers.