The music clefs are musical symbols placed at the beginning of the staff.
There are 3 music clefs :
G Clef (Treble)
F Clef (Bass)
The clefs are placed very precisely on one of the five lines of the stave. They are setting the name but also the pitch of the music notes.
The Treble G (sol) clef is the most used. It is placed on the 2nd line of the staff. So, the music note placed on the 2nd line of the staff is a G (sol) :
The Treble clef is used on sheet music for piano (right hand), guitar, violin, flute, oboe, clarinets, saxophones, horn, trumpet... For the singers, the Treble clef is used with the following voices: tenor, contralto, alto, mezzo-soprano, soprano.
The F (fa) clef located on the 4th line of the staff is called Bass Clef (the F clef on the 3rd line is now only used for musical transposition). If the F key is placed on the 4th line, the music note on the 4th line of the music staff will be a F and the names of other notes of the scale will change accordingly:
The Bass clef is used on sheet music for piano (left hand), cello, double bass, bass guitar, bassoon, trombone, tuba, timpani... Baritone and bass voice use the Bass clef too.
The C clef can be placed on the 1st, 2nd, 3rd or 4th line of the staff. If it is placed on the first line of the staff, the music note written on the first line will be a C, etc.
If the C clef is placed on the second line of the staff, then the music note placed on the second line will be the C and the names of other notes of the scale will change accordingly.