Gebunden
Legato, executed with a slur.
What it means
Gebunden (“connected”) is the German equivalent of legato: the notes are strung together without an audible gap, so that a continuous line arises. Each note is attacked individually, but the preceding one ends only when the next begins.
Connecting is to be distinguished from holding. A slur over notes of different pitch means connected playing; a curve between two notes of the same pitch is a tie and means that the note is not attacked anew but held over both values. The signs look the same, the execution is different.
The counter-term is separated playing, from the light non legato to the short staccato. In between lie portato and mezzo staccato.
In the notation
Connected playing is indicated by a slur above or below the notes concerned. The slur runs on the side facing away from the stems. With winds and strings it has an additional meaning: it indicates what is to be played in one breath or in one bow stroke. In piano music, by contrast, it designates the articulation alone and often the phrasing at the same time.
Musical use
Connected playing is the basic form of singing music: melodies that are to sing are performed connected. In slow movements it carries the long line, in accompaniment figures it provides a soft ground. In polyphonic textures the connection serves to make the course of a voice audible when several voices run at the same time.
Gebunden is notated with a slur. Strings play the notes in one stroke. Winds attack only the first note. The pianist connects the notes by finger legato.
Performance practice
Watch the transitions, not the notes: a line arises where two notes meet. On the piano this means to release the key only when the next is pressed; with winds, an even air flow without tongue stroke between the notes. With strings, take care that the bow change does not become audible. And, when reading, distinguish carefully between slur and tie.