Question: What is the full scale of the keyboard/piano, and what is the first note on the keyboard?Patience (Salem, South Carolina, USA)
Albert's reply: The first key on the standard, 88-key piano is A, and the top note is C.
However, the piano's compass (its range of notes) has changed significantly throughout the instrument's history. When the piano was invented around 1700 (see Who Invented the Piano?, its compass was only about four octaves. (The interval from any note to the next higher or lower note of the same name—from C to C, D to D, E-flat to E-flat, etc.—is an octave.)
The piano's range has steadily increased since then, to five octaves in Mozart's day (1756-1791), six in Beethoven's (1770-1827), and seven and one-third (88 keys) today. When he published his Piano Sonata, Opus 101 in 1818, Beethoven even wrote "Contra E" below the low E at one point—contemporary pianists might otherwise have considered it a mistake since their pianos only extended down to F!
Today, the piano with the widest compass is the Bösendorfer Imperial, built at the turn of the 20th century. It has an extra nine keys in the bass, which extends all the way to sub-contra C—eight full octaves. While a few composers have written for the Imperial—among them Debussy, Ravel and Bartók—the extra keys are mostly there to add resonance to the bass notes that actually are played. In fact, the Imperial's lowest keys are so low in pitch that they're beneath humans' ability to hear them!