Many different values has this word. Key - spring clean, fresh and cool spring water. The key from the lock, which lock the apartment, gate or suitcase. Wrench, without which it can not be repaired bike, not to fix the water heating system. Finally, the most interesting key - the key to the cipher, which allows you to read the mysterious message. This last meaning of the word key is more reminiscent of his musical sense. Indeed, to read some of the notes, the key is absolutely necessary, otherwise the entry will be encrypted. See, for example, the following line:
Despite the simplicity of the melody, no musician will not be able to play it until at the beginning of the score lines (they are called "stave" or "notonous"), dotted notes, will not be delivered to some key. After all what is written here notes, unknown! You can see how they relate to each other (approx: we can only guess where the intervals between sounds great, but where is small), defined their rhythm. Now put the key:
All at once it became clear (of course, for those familiar with the notes). Right? You can have that and the first record transcribed as well? Will be wrong. It can be read as follows:
Will other notes, another octave, another mode and even the other way.
So what is the key? This sign, which is always placed at the beginning of the stave and specifies the position of one of the notes, and depending on her and everyone else.
In the distant past of the keys was used a lot, and the most common were the keys that define the position of the notes to the first octave. Why did you need a lot of keys? Judge for yourself: five lines of the notes and between them can comfortably record only eleven sounds. In music, it is used much more. For the rest we should add an additional line, and it is very clutter the record and makes it difficult to read.
The output, of course, was found. Most prevalent in those days was vocal music. But the range of the human voice is quite limited. So each performer can comfortably record his party, if you place it accordingly. For example, a soprano is a high voice. He sings mainly in the first, and often in the second octave. Baritone, on the contrary, it sounds down from the defining note. Therefore, the key to for soprano and baritone is not the same. Soprano is on the first line, so you can write notes up, sang baritone parts in front, on the fifth: his party, recorded on the same five lines, reads much lower. And between them, respectively the second, third, and fourth lines are mezzo-soprano, Alto and tenor keys.
Ring in the middle of the sign every time determines the position of the note of the first octave.
Of course, these keys were used not only by singers. They were comfortable and some tools. So, still works for viola and his party in the orchestral scores written in Alto key. Applied sometimes and tenor key. But gradually with the development and increasingly widespread instrumental music was that all of these keys still do not provide enough convenient account that does not cover the extreme registers. Then came the other keys that define the position of the notes Sol of the first octave and f small octave. Several such keys over time in musical practice has only bass violin and . They are convenient because as "linked" between a note to the first octave, which was located on the first lower extension in the treble clef and the first upper extension in the bass. Together, these keys provide the ability to record almost all of the scale and therefore have become universal. Here they are (curls both keys show the position on the staff defined their music):
It remains to say how they came by these icons: , , . This greatly changed over time Latin small letter a With (i.e. before), G (G) and F (FA).