The noun 钢琴家 (gāngqínjiā) means "pianist" and is formed by adding the suffix 家 (jiā), meaning "specialist" or "expert," to 钢琴 (piano). This pattern of adding 家 to a field or skill is a productive way to form professional titles in Chinese.
她是一位非常有名的钢琴家。
tā shì yí wèi fēicháng yǒumíng de gāngqínjiā.
She is a very famous pianist.
那位钢琴家的演奏让全场观众感动落泪。
nà wèi gāngqínjiā de yǎnzòu ràng quánchǎng guānzhòng gǎndòng luòlèi.
That pianist's performance moved the entire audience to tears.
他的梦想是成为一名钢琴家。
tā de mèngxiǎng shì chéngwéi yì míng gāngqínjiā.
His dream is to become a pianist.