Beams are thick¹ straight lines used to group notes smaller than a quarter note into metric units. A straightedge should always be used when drawing them. The most common use for the beam is to connect two or more notes which are parts of the same beat. If the beat is a quarter note, eighth notes will be beamed in groups of two; if the beat is a dotted quarter note, eighth notes will be beamed in groups of three. Beams should show the meter.²

A beam can combine notes on different beats into a larger unit. For instance, in a measure, beats one and two and beats three and four may be grouped together,³ although in simple time any beat divided into more than two parts cannot be connected to another beat. Notes (or rests) whose values cross the center of the measure must be broken into tied notes or two rests to permit visual identification of the middle of the measure.

In time, a beam can combine similar notes on one beat and similar notes on adjacent beats. This means that the first and second beats can be beamed together, as can the second and third, or even all three beats. In time the unit can include similar notes of one or both beats. In time, a unit may consist of all notes of each of the two beats in the measure. It is not possible to combine six eighth notes into one beamed unit in meter since this would appear as a unit. Beaming ‘across the beat’ should be avoided unless it is an exceptional circumstance, for instance when beaming across the beat and/or bar line is used to show irregular groupings.

² As far as possible, notes below the value of a quarter note should be grouped according to the pulse shown by the time signature: . When unequal notes occur in a group the division should be in accordance with the time signature: becomes either or .

³ Regular groups of eighth notes, etc., are often unconventionally connected: . Such connecting, however, should not be used for a beam containing more than three beats, and when the group is accompanied by notes of longer value it often looks better to divide them in accordance with the latter.