Piano Forum

I know it's been a long time since your initial post, but I just found this thread while searching for different opinions on how to phrase and accent the grace notes in this piece, so maybe others who find themselves here can benefit from my answer.

Using 3-4-5 to play the grace notes in MS. 6 (or MS. 5 if you don't count the pick-up bar) could be a problem because of 2 issues:

1. The ring finger and pinkie both are controlled by the Ulnar Nerve, and because of this, nerve impulses often trigger both fingers at the same time, causing difficulty in achieving finger independence. The ring finger also shares the Median Nerve with the rest of the hand, but the overlap between the pinky and ring fingers cause neurological signals to cross all the time. This can be re-programmed in some cases, where the Median nerve is used to send signals to the ring finger independently of the pinky, but varies from student to student.

Hanon exercises and scales attempt to rectify this but without the knowledge of the physiology of the built in obstacle in the physical structure of the nerves in the hand, which can cause repetitive strain injury if a person forces the issue. Playing fast passages with pinky and ring thus can become difficult and cause problems above and beyond any discussion of skill or talent or lack thereof.

Source: I'm a piano teacher.
also, https://orthoinfo.aaos.org/topic.cfm?topic=a00069

2. The score calls for the use of the thumb on the first grace note in that measure, setting up the hand position to be 1-2-3 for those notes and then the score calls for the 4th finger to be used for the high A in the F#-A interval on the 2nd 8th note of the measure. This is less of a strain on the hand and wrist, and allows the piece to be learned in note clusters that can be memorized in visual patterns which are instantly easy to understand and physically less difficult to play.

I'm sure that since it's been like 8 years since you posted this you have figured this out by now but maybe my post can help the next random person who is looking for advice.