Slur (musical notation)

Overview

A slur is a curved line that spans two or more noteheads in a musical score. Unlike a tie, which connects two identical pitches to lengthen their combined duration, a slur groups notes of differing pitch to indicate a single, continuous, legato phrase or to shape musical expression. The line does not affect rhythm or pitch; its purpose is purely articulatory, guiding the performer to connect the notes smoothly, often with a subtle change in dynamics or emphasis.

In practice, a slur may also convey stylistic nuances such as a breathless phrase, a lyrical line, or a specific articulation prescribed by the composer. While the visual cue is simple, the interpretive possibilities are broad, and performers rely on contextual clues—tempo, dynamics, and surrounding markings—to realize the intended effect.

How It’s Notated

The slur is drawn as a single, gently curving line that starts at the first note of the group and ends at the last. It is placed above the staff for notes that are primarily on or below the middle line, and below the staff for notes that sit mainly on or above the middle line, to avoid collision with stems, accidentals, or other symbols. When a note has a stem, the slur attaches to the side of the notehead opposite the stem; if the note is beamed, the slur typically arches over the beam, maintaining a clear gap. Exceptions include slurs that begin or end on a rest—here the line connects to the nearest notehead, and the rest is left unmarked.

How It’s Performed

When a performer sees a slur, they aim to produce a legato articulation: each note is played without a perceptible separation, often using a single bow stroke on strings, a continuous breath on wind instruments, or a smooth finger transition on piano. The exact execution depends on the instrument: string players may use a single bow direction; pianists employ a connected touch with minimal pedal; vocalists shape a seamless phrase with breath control. Dynamics may be subtly adjusted—often a slight crescendo at the start and a decrescendo at the end—to further emphasize the phrase.

Origin

The slur evolved from early Baroque ornamentation symbols, where curved lines indicated expressive phrasing. By the mid‑18th century, composers like Carl Philipp Emanuel Bach used a standardized, smooth curve to denote legato passages. The modern shape and placement conventions were solidified in the 19th‑century editorial practices of publishers such as Breitkopf & Härtel and later codified in notation manuals like the International Music Score Library Project (IMSLP) and the American Music Notation Society guidelines.

Where You’ll See It

Slurs appear across virtually all Western art‑music repertoire, from Baroque suites to contemporary orchestral works. They are especially prevalent in lyrical genres—operatic arias, Romantic piano nocturnes, and Romantic string passages—where phrasing is central to expression. In popular music transcriptions, slurs also indicate smooth vocal lines or guitar legato techniques. For deeper historical context, see Silo 7 (Music History & Eras) and Silo 4 (Genres).

Common Misconceptions / Confused Symbols

Because many articulation marks look similar, musicians often confuse slurs with other symbols. Clarifying these differences helps avoid misinterpretation.

• Misconception: A slur and a tie are the same because both are curved lines.
  Correction: A tie connects two identical pitches to extend duration; a slur groups different pitches for legato phrasing.
• Misconception: A slur always indicates a louder dynamic.
  Correction: A slur indicates smooth connection, not volume; dynamics are indicated separately.
• Misconception: Staccato dots placed inside a slur mean the notes should be both legato and detached.
  Correction: When staccato marks appear inside a slur, the performer must balance the articulation—often playing a light, slightly detached legato.
• Misconception: A phrase marking (a larger, double‑curved line) is the same as a slur.
  Correction: Phrase markings group larger sections for expressive shaping, while slurs affect immediate note‑to‑note articulation.
• Misconception: A slur can be placed on rests to indicate a pause.
  Correction: Slurs do not attach to rests; they connect notes only, though a rest may appear within a slurred phrase without being marked.