Moonlight mvt 2 fingering

Question

I'm learning Beethoven's "Moonlight" movement 2, and I'm unsure of the fingering for the left hand here. What does it mean with two sets of fingering in bar 49?

I understand that the d flat is held, but which fingers should I switch and when?

Answer 1

Whenever you see two fingering numbers for the same note (e.g. the 2-1, 5-2 and 3-2 in the diagram), play the note with the first finger number in the pair. Then, while holding down the note with that finger, make the second finger number in the pair also hold down that note, then let go of the first finger number.

The timing can get tricky, but do whatever timing is the most comfortable.

For example, I very strongly suspect that executing the 2-1 swap in the D flat, then executing the 5-2 swap in the B flat will be a LOT more comfortable than trying to hold down both notes with the pointer finger at some point.

Answer 2

the answer to your question is pretty simple and straightforward:

• one finger aims at playing the higher note;
• the other finger aims at playing the lower note;