Sweet
Lovely, dolce.
What it means
Süß is the German equivalent of the Italian dolce and calls for a lovely, soft performance. What is meant is a sound without hardness: a round attack, bound lines, restrained dynamics, hardly perceptible accents.
The marking concerns tone production and expression, not tempo. It nonetheless has an indirect effect, because a sweet performance tolerates no haste.
Among the words for gentleness the differences lie in the colouring. Zart means fineness, sanft mildness, süß the lovely, pleasant softness. Its superlative is sehr süß, in Italian dolcissimo.
In translation the German word seems unfamiliar today; in the notated text it is nonetheless a common and precise marking.
In the notation
The word stands above the staff, in German-language editions in place of dolce, and applies until a new marking. In piano music it can stand over a single voice and then designates which line is to be led particularly softly.
Musical use
The designation is used in lyrical sections, in secondary themes, in songs of a delicate character, and in closing turns that are to fade softly. In German-language music of the nineteenth century it often stands where composers deliberately avoid the Italian terms.
German performance markings of this kind are found above all in the art song of the nineteenth century. It stands in German Romantic scores, especially in songs and character pieces. The articulation is bound, the dynamics usually soft, the tempo calm. Hard accents and sharp attacks contradict the character. The tone should be warm and singing, carried by an even legato. Care must be taken that the sweetness does not become saccharine or powerless: even a delicate expression needs tension, direction, and a clear phrasing, so that the melody keeps its arc.
Performance practice
Watch the attack of every note: softness arises there and not in the volume. Avoid accents and lead the transitions carefully. Keep the accompaniment soft and even. And keep the tone sustaining — lovely does not mean weak.