The musical instrument associated with a symphony orchestra and featuring keys is the piano. The piano is a versatile keyboard instrument that produces sound through hammers striking strings when the keys are pressed. It plays a central role in various musical genres and is widely used for both solo and ensemble performances. In orchestral settings, the piano can contribute to harmony, melody, and texture, complementing a variety of instruments. With its unique ability to produce both soft and loud dynamics, the piano is cherished for its expressive capabilities and is a favorite choice for composers and performers alike.