The keys of G, C and E can mean G major or G minor, C major or C minor, E major or E minor, but they are generally abbreviations of G major, C major and E major. Let's list what these three major forms are.
1. G Major is a major mode with G as the center sound. The parallel minor is E minor, and the staff is counted as a sharp sign. The scales of G natural major are G, A, B, C, D, E, #F, G
2, and C Major is a natural major of music that begins with the sound C, and consists of C, D, E, F, G, A and B, which is a key without sharp sign and flat sign.
3. E Major is a major based on the sound of e, which consists of e, #F, #G, a, b, #C, #D and e. key signature has four sharp signs.
extended information
key signature?
In order to establish a new palace system, the phonetic symbols needed are recorded after the clef in a certain order and position. These symbols are called key signature. Key signature always uses only the same kind of inflection marks, that is, the rising or falling marks.
Introduction to key signature
The diacritical mark written after the clef in the staff is called key signature. In modern European music theory, the reason why the tonality is expressed by key signature is because the concept of tonality in Europe is often grasped by its expression on keyboard and staff.
The same natural heptatonic scale, when the player chooses different laws from the twelve laws to form different key ranges, it shows different key selection methods on the keyboard.
because black keys's notation on the staff is represented by adding # or b in front of the notes of the white key phoneme, a number of black keys included in the key range is also represented by a number of # or b on the staff, and these ascending and descending marks are written on the left side of each line of the staff table and the right side of the clef, which becomes the symbol of the key range used by the music.
Baidu Encyclopedia: key signature.