How to get the shield key – Resident Evil remastered

Go to the east wing of the mansion (2F). Find the room with a big table and candles. Inside that room there is a cupboard that can be pushed to the side to reveal a small path. Get the first piece of the musical score from that path.

Go to the west wing of the mansion (1F). Go to the corridor where you found the first zombie then find the room with a piano. Inside that room is another piece of the musical score hidden behind a cupboard.

Combine the two musical scores to get the moonlight sonata.

Go to the piano in the same room then choose the musical score and press use.

While playing, Rebecca will get into the room and offer to help. She will then tell you that she needs some practice first. (See How to save Rebecca – Resident Evil remastered)

While playing, Rebecca will get into the room and offer to help. She will then tell you that she needs some practice first. 

Leave Rebecca in the room and collect the emblem from above the fireplace in the dinning room. If you have already done that, just do any event before coming back to her. (See How to get the emblem key in Resident Evil remastered?)

Go back to Rebecca and you will find that she mastered the musical score. She will play it again and a new door will open in the same room. Make sure you have the emblem.

Get inside that new area and switch the new emblem you will find with the one you got earlier from the dinning room. Note that you won't be able to leave unless one emblem is placed there.

Go back to the big dinning room and place the Golden emblem in the place where you got the first emblem.

Walk to the big clock in the same room and you will find a new puzzle. Turn the large gear to the right two times so that the clock is 6 o'clock.

After solving the puzzle correctly you will find the key behind the clock.