What is the best way to draw a sprite in this situation?

Question

Pixel graphics

A newcomer to this topic, a programming project to create a platformer, decided to figure out how to draw graphics first. I drew several tiles of the floor 64x64,
Then I took the piano also 64x64 I

combined all the elements into a big picture, the piano looks small against the background of the floor, the same problem with the doors.
And here is the main question.
What to do in this situation, stretch the sprite programmatically, divide the piano into 2 or more tiles, or ...