The Keys

The picture above shows the 61 keys of a keyboard. The keys are named C-D-E-F-G-A-B and they are repeated 5 times. Each range from C to the next C is called an octave. The frequency of the tone produced by a next higher C is twice as high as the original C. This is the same for any other key, e.g. if you go from an F to a next higher F the tone will be played with a twice higher frequency. You can alway replace any key you play with a key of the same name elsewhere on the keyboard, it won't sound false.

There are also black keys on the keyboard. They will be refered to as sharps if they replace the white key on the left and are called flats if they replace the white key on the right. E.g. an F# (F sharp) will sound higher than an F and an Eb (E flat) will sound lower than an E.

If you count both the white and black keys then there are 12 steps going from one C to the next higher C. Each step is called a semitone and has exactly the same pitch difference (frequency is + 6%). Play the white C-D-E-F-G-A-B-C keys and you will hear the well known Do-Re-Mi-Fa-Sol-La-Ti-Do scale. The number of semitones between each note in this scale is not the same:

Do ( + 2 semitones = ) Re ( + 2 semitones = ) Mi ( + 1 semitone = ) Fa ( + 2 = ) Sol ( + 2 = ) La ( + 2 = ) Ti ( + 1 = ) Do

It is a rule that all notes of a melody are chosen from the Do-Re-Mi-Fa-Sol-La-Ti-Do scale. But like every rule there are exceptions and that is where the sharps and flats come in. Sharps and flats will also be needed if we want to play a song a bit higher or lower, because it will sound better at a different pitch or because a singer can't sing notes that high or low.

If the Do-Re-Mi-Fa-Sol-La-Ti-Do scale starts with the key C then we say that the song is played in the key C. Now say we want to play higher starting from the F. The rules for the number of semitones (1 or 2) between each note in the scale remains the same. So we will get:

You will notice that the 1-semitone interval between the Mi and the Fa is this time not on the E and F keys but on the A and Bb keys. In this case the black key is called Bb (B flat) because it replaces the B key. It is not called A# because the A key is still in use in this scale.

Another easy scale with only 1 black key is the key G:

In this key the F is replaced with the F# (F sharp) to match the intervals in the Do-Re-Mi-Fa-Sol-La-Ti-Do scale.

All other scales will need more sharps and flats. In music notations the key is represented with a few sharp or flat symbols at the beginning of the staff. The notes on these specific lines should be replaced with a sharp or flat. If a singer asks a pianist to play the accompaniment for a song, then besides the song title he or she will also mention the key to play it in.

As mentioned the key is not represented with it's name but with a number of sharps or flats. To determin which keys are replaced I would recommend the following method. Think of the keyboard as devided in small (C thru E) and large (F thru B) groups of keys corresponding with the 2 and the 3 black keys. If you have to raise a number of keys because there are a few sharps pictured in the key then you start with raising the first key in the large group (F becomes F#). Then the first key in the small group (C becomes C#). Then the second key in the large group (G becomes G#). Then the second key in the small group (D becomes D#). Then the third key in the large group (A becomes A#). So select keys starting from the leftmost key in a group in the order large-group, small-group, large-group, small group, large group.

Example: The key shown above has four sharps. The keys to be raised are F (first key in the large group), C (first key in the small group), G (second key in the large group) and D (second key in the small group).

For keys with flats it is the same story but now you lower the selected keys and you start with the highest key in the group. So the selecting order for flat keys is: B becomes Bb, E becomes Eb, A becomes Ab, D becomes Db and G becomes Gb.

Always check which keys are raised or lowered in the given key before you start playing.


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