Acoustical Instruments - a Bad Idea??

When playing music on one’s audio system, is it a bad idea to have certain acoustical instruments in the room?

I just moved, and was thinking of purchasing an upright or maybe a small grand piano placed in the same room as my speakers.  Then I realized that the piano strings may start sympathetic vibration to the audio music adding room distortion.  Maybe any stringed instrument in the room is a bad idea. Drum cymbals, or anything bell like a glockenspiel..

What do you think?