The piano (a word that in Italian means "soft", and in this case is the apophope of the original term, "pianoforte", which referred to its soft and strong nuances) is a harmonic musical instrument classified as a keyboard instrument and percussive strings By the traditional classification system, and according to the classification of Hornbostel-Sachs is a simple cordófono. The musician who plays the piano is called a pianist.

It is composed of a soundboard, to which has been added a keyboard by which steel strings are pierced with felt-lined macilli, producing the sound. The vibrations are transmitted through the bridges to the harmonic table, which amplifies them. It is formed by a chromatic chord of multiple strings, driven by an indirect percussion mechanism, to which it has added erasers. It was invented around the year 1700 by the Paduano Bartolomeo Cristofori. Among his predecessors are instruments such as the zither, monochord, dulcémele, harpsichord and harpsichord.

Throughout history there have been different types of pianos, but the most common are the grand piano and the vertical or wall piano. The tuning of the piano is a primary factor in the acoustics of the instrument and is done by modifying the tension of the strings so that they vibrate at the appropriate frequencies.