The musical instrument that has 88 keys is the piano. This versatile instrument typically includes 52 white keys and 36 black keys, allowing for a wide range of musical expression across various genres. Pianists can play melodies, harmonies, and complex compositions, making the piano a favored choice in classical, jazz, and popular music. The layout of keys enables easy access to different musical notes and chords, while techniques such as dynamic playing and pedal use enhance its musical capabilities.