Commonly used Musical Signs
Dynamics
Dynamics are indicators of the relative intensity or volume of a musical line. | Pianississimo1
Extremely soft. Very infrequently does one see softer dynamics than this, which are specified with additional ps. | | Pianissimo
Very soft. Usually the softest indication in a piece of music, though softer dynamics are often specified with additional ps. | | Piano
Soft. Usually the most often used indication. | | Mezzo piano
Literally, half as soft as piano. | | Mezzo forte
Similarly, half as loud as forte. If no dynamic appears, mezzo-forte is assumed to be the prevailing dynamic level. | | Forte
Loud. Used as often as piano to indicate contrast. | | Fortissimo
Very loud. Usually the loudest indication in a piece, though louder dynamics are often specified with additional fs (such as fortississimo – seen below). | | Fortississimo1
Extremely loud. Very infrequently does one see louder dynamics than this, which are specified with additional fs. | | Sforzando
Literally "forced", denotes an abrupt, fierce accent on a single sound or chord. When written out in full, it applies to the sequence of sounds or chords under or over which it is placed. | | Crescendo
A gradual increase in volume.
Can be extended under many notes to indicate that the volume steadily increases during the passage. | | Diminuendo
Also decrescendo
A gradual decrease in volume. Can be extended in the same manner as crescendo. |

LINES | Staff
The staff is the fundamental latticework of music notation, upon which symbols are placed. The five stave lines and four intervening spaces correspond to pitches of the diatonic scale—which pitch is meant by a given line or space is defined by the clef. | | Ledger or leger lines
Used to extend the staff to pitches that fall above or below it. Such ledger lines are placed behind the note heads, and extend a small distance to each side. Multiple ledger lines can be used when necessary to notate pitches even farther above or below the staff. | | Bar line
Used to separate measures (see time signatures below for an explanation of measures). Also used for changes in time signature. Bar lines are extended to connect multiple staves in certain types of music, such as keyboard, harp, and conductor scores, but are omitted for other types of music, such as vocal scores. | | Double bar line, Double barline
Used to separate two sections of music or placed before a change in key signature. | | Bold double bar line, Bold double barline
Used to indicate the conclusion of a movement or an entire composition. | | Dotted bar line, Dotted barline
Subdivides long measures of complex meter into shorter segments for ease of reading, usually according to natural rhythmic subdivisions. | | Bracket
Connects two or more lines of music that are played simultaneously. In general contemporary usage the bracket usually connects the staves of separate instruments (e.g., flute and clarinet; 2 trumpets; etc.), whereas the brace connects multiple parts for a single instrument (e.g., the right-hand and left-hand staves of a piano or harp part). | | Brace
Connects two or more lines of music that are played simultaneously in keyboard and harp music. Depending on the instruments playing, the brace, (occasionally called an "accolade" in some old texts), will vary in designs and styles. |