What now?

Re the piano.  It may not be 5 foot by 7 foot.  It could be an upright, 5.5 foot by 1,8 foot.

Yes the strings will vibrate to the tune of the sound waves from the hi-fi.  But pianos have a pedal that can damp all the strings by lowering felt pads on them.  Using a lever and a wedge, the pedal can be rigged so that it damps the strings full-time.

Ohm Walsh 1000s are what first came to my mind.  

Ok, thanks all for the suggestions. Here's an update, and I hope you're still with me.  I described this bedroom/listening room.  It is about 12x15 with a 10' ceiling. The south (12') wall has a Yamaha electronic piano.  Also on this wall is my turntable and other components. The head of the bed is against the north (12') wall.  The bed is 34' high (storage underneath).  At the foot of the bed, about 6' from the south wall, is a chest of drawers (33' high). I began this thread asking what floor standing speakers I might use on either side of the piano and close to the south wall. I appreciate the suggestions for the Ohm, and have talked with the fellow there, who suggests the tall 1000.  That's well within my budget.  My concern is with the sound stage of the omnidirectional speaker.  I understand that I can return the Ohm's if they don't work for me, but I want to avoid doing that if I can.  I am generally concerned that even with a good-sized floor speaker, the sound, especially the higher frequencies, will be coming from well below my head when I am sitting on the bed.  So ... it has occurred to me that I might put two good bookshelf speakers on the chest of drawers, facing the head of the bed, on low stands that would raise them the a few inches to the ideal height.  The could be about 5' apart, and 6' from the south wall.  The would also be about 7' from my head. Of course, that would require that I run speaker cable to the from the south wall, along the east wall, along the north wall to the bed, then under the mattress to the speakers (probably 25 to 30' in all).  However, in terms of speaker placement, this seems promising.  What do you who know much more than I think?   And, if you think this would be better than anything I can do on the south wall, what specific speakers would you recommend at, say, $3000 or under, new or used?

For $3k you can purchase a pair of Martin Logan Spires used that will blow you away. I’ve seen several sets available for sale recently. But you won’t drive them with a receiver. Great speakers. Nothing near them at that price. Originally $9k new. 

there are literally 2-3 posts every week in the speaker section asking for recommendation in the 2-3-4-5 grand range, with 100s of comments