aka the "C" clef ... the middle line is the note "C".
The base clef is also called the f clef, because if you look at it, the line in between the two dots of the base clef when it is on a staff is the f line.
The Great Stave is the combination of both the treble clef and the base clef
bass clef
violas dont use treble clef they use alto clef
Bass and also tenor clef.
If you mean which clef does a violinist use then it's the treble clef
The 'Cello is in Concert Pitch (C) so A above middle C will equal 440 (same as the piano)
treble clef
Bass clef.
The piano uses both the treble clef and the bass clef.
A major 2nd below A is G.