Treble clef
The treble clef is the sign at the start of a staff that fixes the second line from the bottom as G, the G above middle C. That is why it is also called the G clef.
The curl of the clef wraps around the second line: the G line. All other notes are counted from it. The lines, from the bottom, are E, G, B, D, F; the spaces are F, A, C, E, which spell “face”. Middle C sits on the ledger line below the staff.
The treble clef is used for higher notes: in piano music it is usually the right hand, the upper staff of the grand staff. Violin, flute and most singing voices are written in it too, which is where the name comes from.
At the start it helps to learn a few landmark notes, middle C on the ledger line, G on the clef line, C in the third space, and read the other notes as steps from the nearest one.
Where it is taught: the studio’s interactive textbook, chapter 1, “The keyboard and your first notes”.