[ligato] (It.: ‘bound’; Fr. lié; Ger. gebunden)
Of successive notes in performance, connected without any intervening silence of articulation. In practice, the connection or separation of notes is relative, and achieved through the presence or absence of emphasis, Periodicals, and attack, as much as silences of articulation; degrees of connection and separation vary from legatissimo (representing the closest degree of connection), tenuto, portamento, legato, portato, non legato, mezzo-staccato, Staccato (the natural antonym of legato), to staccatissimo, and some of these terms have connotations going beyond simple degrees of connection or separation.
In 20th-century notation, legato is generally indicated by means of the Slur across a succession of notes; the beginnings and ends of slurs are now generally marked by articulations (of bowing or tonguing in string and wind instruments, and of phrasing in keyboard instruments). The slur often, however, had a vaguer general meaning of ‘legato’ in the 18th and early 19th centuries. Successions of notes in modern notation are seldom left without any indication of articulation, but if they are, the performer will normally presume that a legato style of playing is called for....