A slur is a musical notation symbol used to indicate the grouping or connection of two or more notes. It is represented by a curved line placed above or below the notes.
The primary function of a slur is to indicate that the connected notes should be played smoothly and legato, without any separation between them. It signifies a musical phrase or passage that should be performed in a connected and flowing manner. Slurs are often used to indicate melodic lines, where the notes are to be played in a seamless and expressive manner.
In addition to indicating legato playing, slurs can also convey other musical instructions. For example, a slur may indicate a phrase or section that should be played with a specific dynamic or articulation, such as a crescendo or a decrescendo. Slurs can also be used to indicate phrasing and musical interpretation, helping performers to shape the music and convey the composer's intentions.
It is important to note that a slur is different from a tie, although they may appear similar. A tie connects two or more notes of the same pitch, indicating that they are to be played as a single, sustained note. A slur, on the other hand, connects different pitches and focuses on the smoothness and legato articulation between them.