Soprano clef
The C clef on the first line.
What it means
The soprano clef is the C clef on the lowest line of the staff: there lies middle C. It was the clef of the topmost singing voice in vocal music before the nineteenth century and is out of use today — modern editions write the soprano part in the treble clef. Whoever works with urtext editions, facsimiles, or older scores, however, encounters it regularly.
In the notation
The sign is the same as for the alto and tenor clefs; only its position distinguishes them. The meeting point of the two curves lies here on the first line from the bottom. From this it follows that the whole tonal range of the soprano voice can be represented without ledger lines — this was precisely the point. Compared with the treble clef, the same notation appears shifted by a third, which becomes the well-known trap when reading, if one tries to convert instead of reading anew.
Musical use
In vocal scores of the sixteenth to eighteenth centuries, every voice carried its own clef, and the soprano clef was the normal case for the upper voice. In figured-bass scores and in Italian cantata manuscripts, too, the singing voice usually stands notated this way. Modern scholarly editions usually transcribe into the treble clef but give the original clefing in the critical report; facsimiles and some urtext editions retain it. In the context of the Renaissance, the choice of clef also plays a role in the disputed question of the chiavette.
The soprano clef is to be distinguished from the other C clefs only by the line it stands on — sign and principle are identical.
Performance practice
Learn this clef too by way of an anchor note rather than by converting: middle C lies on the lowest line, everything else results as a distance from it. If you sing from an old source, note down the starting note in familiar notation at the beginning and rely afterward on the distances. Practise short, well-known melodies at sight in this clef, so that notation and sound connect directly.