In music notation, a note value indicates the relative duration of a note, using the color or shape of the note head, the presence or absence of a stem, and the presence or absence of flags/beams/hooks/tails.
A rest indicates a silence of an equivalent duration.
The breve appears in several different versions, as shown at right.
Sometimes the longa is used to indicate a very long note of indefinite duration, as at the end of a piece.
When a stem is present, it can go either up (from the right side of the note head) or down (from the left side, except in the case of the longa). In most cases, the stem goes down if the notehead is on the center line or above, and up otherwise. Any flags always go to the right of the stem.
When two or more notes which would normally have flags (eighth notes or shorter) appear successively, the flags may be replaced by beams, as shown at right. Notes are typically beamed only if they appear in the same beat within the bar.
A note value may be augmented by adding a dot after it. This dot adds the next lower note value, making it one and a half times its original duration. A number of dots (n) lengthen the note value by Failed to parse (Missing texvc executable; please see math/README to configure.): \tfrac{2^n - 1}{2^n}