Fingering and how it is written – free music theory course

On the piano, fingers are numbered 1 to 5, from thumb to little finger, for both hands. So the thumb is 1 on the right as well as on the left: that makes the numbering symmetrical.

Finger	thumb	index	middle	ring	little
Number	1	2	3	4	5

On the score, fingering numbers are written above the notes for the right hand and usually below for the left hand. Editors only mark the useful ones: at the start of a passage, at a change of position, at a thumb crossing.

Five-finger position

M:4/4
L:1/4
Q:1/4=90
K:C
!1!C !2!D !3!E !4!F | !5!G4 | !5!G !4!F !3!E !2!D | !1!C4 |]

Left hand, same melody an octave lower: fifth finger on C, thumb on G.

M:4/4
L:1/4
Q:1/4=90
K:C clef=bass
!5!C, !4!D, !3!E, !2!F, | !1!G,4 | !1!G, !2!F, !3!E, !4!D, | !5!C,4 |]

The thumb crossing

To play more than five notes in a row, the hand must change position without a break: the thumb passes under the hand (or a long finger crosses over the thumb). C major scale, right hand:

M:4/4
L:1/4
Q:1/4=80
K:C
!1!C !2!D !3!E !1!F | !2!G !3!A !4!B !5!c |]

Finger substitution: changing fingers on a held key (marked "4-3" or with a small arc between two numbers) to keep the legato.
Repeated notes: often 3-2-1 for a fast repeated note, easier than using one finger.

Follow written fingerings from your very first reading. A random fingering repeated ten times becomes a habit that is hard to undo. If a fingering doesn't suit you, choose another one deliberately, pencil it in, and stick to it.

Don't be fooled: some old British editions ("English fingering") marked the thumb "+" and the other fingers 1 to 4. If an old score looks illogical, check for this! And guitarists number from 1 (index) to 4, without the thumb.