The beam — it changes the reading, not the sound
Five pairs to listen to. Each pair holds the same notes, set differently — and both versions sound identical, note for note.
Two eighth notes sound the same whether each carries its own flag or both sit under one beam. The beam tells the player nothing about length, volume or touch; it tells the reader what belongs together. That is exactly what makes it valuable: it turns a row of identical noteheads into a bar you can count at a glance.
Five pairs stand side by side here, each set one way and then another. Both versions can be played, and you hear no difference — onsets, durations and pitches are the same note for note. The whole difference is in the picture.
This is not a detail. Beam a bar wrongly and you write something that is counted differently from how it sounds: six eighths in groups of two read as three-four, the same six in groups of three read as six-eight. The sound does not settle that question; the picture does.
Flags or beams
Eight eighth notes, each with its own flag — correctly counted, but laborious to read. Beside it the same eight under two beams. Not a single note changes: the recordings are identical note for note, onset for onset. What changes is the time the eye needs. In printed music single flags therefore appear almost only where a note stands alone on its beat.
Beam groups in four-four
Eight eighths again, beamed both times — on the left under a single beam, on the right under two. Both are the same music, and both are legible; but the right-hand picture shows where the halves of the bar lie, and the left one hides it. In four-four you therefore group by half bars, and where things move fast, by quarters. The beam is information about the metre, not about the notes.
Two groups of three in six-eight
Six eighths in 6/8. On the left they stand in three groups of two, on the right in two groups of three. The notes are the same in both pictures, and the recordings sound alike — but they are counted differently: 6/8 has two beats of three eighths each, and only the right-hand picture says so. The left one looks like three-four and is read that way.
The second beam on sixteenths
An eighth and two sixteenths, twice in a row. On the left each note carries its own flag; on the right a continuous beam lies across the group and a second, shorter one above it — exactly as long as the two sixteenths. The number of beams names the note value: one beam eighths, two beams sixteenths, three beams thirty-seconds. That holds for each beam separately, even inside one group.
The beam runs across the rest
A short rest in the middle of the figure. On the left it breaks the group: the first note stands alone with a flag, the last two get a beam of their own. On the right a beam runs straight across the rest, and all four positions stay readable as a group. The sound is the same either way — the rest stays a rest. Which spelling you choose decides whether the figure is seen as one unit or as two fragments.
What the grouping follows
The rule is short: a beam gathers what falls on one beat. In four-four that means four eighths at a time — one group for the first half of the bar, one for the second, so the middle of the bar stays visible. A single beam across all eight would not be wrongly counted, but it hides the very place where you count.
In six-eight the same rule gives a different picture, because that metre counts in two threes rather than three twos. So two groups of three stand there. Beam the same six eighths in twos and you have written a three-four bar to the eye — the reader counts it wrongly, though every note sits where it belongs.
Two refinements follow. Sixteenth notes under a beam take a second, shorter beam; it lies above the first and runs only as far as the sixteenths themselves. And a rest does not necessarily break a beamed group: in quick figuration the beam runs straight across it, so the group stays readable as a group.
What sits alongside
The note values and their lengths: Note values. Which time signature is counted how: Time signatures.
Music symbols · Music notation glossary
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Photograph a page of sheet music or play the melody — Anotona finds the key, engraves the notes and transposes them into any other. Free.
See AnotonaEvery note on this page is computed, not typed in — following the rule that also makes F# major spell its seventh degree E#, not F.