My sentence is
He plays the piano & the violin.
Is it correct to say
He plays the piano & violin?
My sentence is
He plays the piano & the violin.
Is it correct to say
He plays the piano & violin?
"He plays the piano." and "He plays piano." are both acceptable. However, a basic rule of style is to be consistent when choosing between two acceptable forms. So, I suggest either "He plays the piano and the violin." or "He plays piano and violin.", but not "He plays the piano and violin".