This Poll:
All Polls:
Elizabeth
It should be : He plays the piano.
GP
"He plays the piano" is the only correct form.
Interesting how many people believe that the majority is always right.
Pinoy
This poll isn't about good, acceptable, or bad; it's about right or wrong. And the sentence "He plays piano." is wrong.

Rouyer JL
I was taught that the only good English is "He plays the piano"