Bass clef

The bass clef does the same job as the treble clef, but for the low register. Its sign has two dots that hug the fourth line (counting from the bottom) and fix F3 there.

With F fixed, the rest of the notes fall into place following the usual order. The five lines, bottom to top, are G, B, D, F, A. The four spaces, bottom to top, are A, C, E, G.

One important thing: the same position on the staff is not the same note in treble clef as in bass clef. The second line is G4 in treble clef, but B2 in bass clef. The clef changes everything.

Middle C (C4) is the bridge between the two clefs: in treble clef it sits just below the staff, and in bass clef just above it, on a ledger line. That's why the piano's two staves meet at middle C.

Seen from the low end, the bass clef notates the low register and joins the treble clef in the grand staff: the two staves are tied together by a brace, the treble staff above and the bass staff below. Middle C (C4) is the first ledger line just above the bass-clef staff, and at the same time the first ledger line just below the treble-clef staff: it is the single shared note and therefore the step up from the bass clef toward the treble clef. This joining is the standard way of writing keyboard music.

If the treble clef is the map of the upper neighbourhood, the bass clef is the map of the lower one in the same city. They share a single corner —middle C— and from there each stretches toward its own area.