Why does a piano have twelve keys in an octave while the staff has only seven note names? Why are there sharps and flats at all? The answer is about a thousand years old.
A staff for seven notes
Medieval singers used a system of seven note names, and the staff of lines and spaces, credited to the monk Guido of Arezzo around the year 1000, was designed for them. Each line and space is one of seven notes. There was no space for any note in between.
The first flat: a round b
The note B was sung in two versions, a softer, lower one and a harder, higher one. Scribes wrote the soft B as a round letter b and the hard B as a square one. The round b became our flat sign, and the square b became both the natural sign and, later, the sharp. That is why the flat still looks like a small b.
More notes, more signs
As music moved through more keys, more notes in between were needed. Instead of redesigning the staff, musicians kept the seven positions and added signs in front of the notes. Later, the signs a piece used all the time were gathered at the start of each line: the key signature.
The keyboard follows the staff
Keyboard instruments grew in the same way: seven white keys for the seven note names, and the extra notes added as shorter black keys between them. The piano you play today is a picture of that medieval seven-note system with five extra keys.
What iCanPiano Style changes
Standard notation shows the black keys indirectly, through signs you must remember. iCanPiano Style draws them directly: a note on a black key is half black and half white, and the black half points to the key.
- F sharp: right half black. Play the black key to the right of F.
- B flat: left half black. Play the black key to the left of B.
- B natural: no natural sign. A note that is all black or all white is played on a white key.
Frequently asked questions
Where does the flat sign come from?
From a rounded letter b, used in medieval music for the soft, lower form of the note B. The square b became the natural and sharp signs.
Why are there no black keys between B and C or E and F?
Because those notes are already a half step apart in the seven-note scale the keyboard is built on, so there is no note between them.