What do vertical numbers above chords mean in a sheet music for the piano?
Never seen this before:
What do the numbers mean? How do I play it? Thanks!
It's the fingering for the notes. I am pretty sure you know that your five fingers can be represented by the numbers 1, 2, 3, 4 and 5, 1 being your thumb and 5 being your pinky. When it is stacked like that, it means to play the chord using those fingers. For the first set of stacked numbers on the left, You use every finger but the middle(3) finger to play that chord. It is by no means fixed to only use that fingering, but it is recommended to do so.
Those are recommendations for fingering the chords. The fingers are numbered with 1 being the thumb and 5 being the pinky.
So in the first chord, labeled 1245, you use all fingers except your middle finger to play the chord, and in the second chord, labeled 125, you only use your thumb, index, and pinky fingers.