noun
pianist
A person who plays the piano, especially professionally.
彼女は有名なピアニストです。
She is a famous pianist.
コンサートでピアニストがショパンを演奏した。
The pianist performed Chopin at the concert.
ピアノ is the instrument itself, while ピアニスト refers to the person who plays it.
Loanword from English 'pianist', ultimately from Italian 'pianista'.