Twenty-two white keys, C3 to C6 — played from the two letter rows.
Octave
C3
Labels
Pedal
Latch
Volume
press a key
Vocabulary
The mapping
Letters are white keys, the row above each is its black keys — exactly where they sit on your keyboard. Pitch rises as you move up the rows. fk58= stay dark: a piano has no black key between E–F or B–C.