The musical instrument that has keys, pedals, and strings is the piano. The piano is classified as a keyboard instrument and is known for its versatility, playing a wide range of musical genres. It contains 88 keys, which produce sound through hammers striking strings inside the instrument when the keys are pressed. Pianos come in various types, including grand pianos and upright pianos, each offering different acoustic characteristics. The pedals allow for techniques such as sustaining notes or creating a softer sound, enhancing the expressive capabilities of the instrument.