When one person plays chess against many opponents at the same time is called a simul.
Chess master , chess player , participant , patzer(a derogatory term) or player .
Generally, you call them chessplayers. But, if their rating is from 1800-2000, they are called an Expert; 2001-2200, Master; 2201-2500, International Master; 2501+, Grandmaster.
You would call a person who praises himself a lot a narcissist.
You would call a person who plays the French horn a "hornist."
A "harmonicanist" is what a person who plays the harmonica is called.
A person who plays in movies is a actor or an actress
PianistA pianist is a person who plays the piano.
a person that plays a cello is called a cellist
You Call Them A Pianist.
Such a person is a Violinist.
A saxophonist plays the saxophone.