Rhythm- an ordered recurrent alternation of strong and weak elements in the flow of sound and silence in speech

Meter- measure of time organization of rhythmic patterns in a composition

Time Signature-a symbol placed at the left side of the staff indicating the meter of the composition.

Simple Duple-two beats to a bar, each divided by two, the top number being "2" (2/4, 2/8, 2/2 …)

Simple Triple-three beats to a bar, each divided by two, the top number being "3" (3/4, 3/8. 3/2 …)

Simple Quadruple-4/4

Compound Duple- two beats to a bar, each divided by three, the top number being "6" (6/8, 6/16, 6/4 …)

Compound Triple-three beats to a bar, each divided by three, the top number being "9" (9/8, 9/16, 9/4)

Compound Quadruple-12/8

Asymmetrical Meter-the beats in the measure can not be divided evenly

Beam-A thick horizontal line that is used to replace the flags of a series of two or more notes that form a rhythmic grouping.

Measure-American term, equivalent to the English term "bar", signifying the smallest metrical divisions of a composition, containing a fixed number of beats, marked off by vertical lines on the staff.

Hemiola-In early music, this term meant the ratio of 3:2, employed musically in two senses: the ratio of the perfect fifth, whose musical value is 3:2, and the rhythmic relation of three notes in the time of two, i.e., the triplet. In the Baroque era

Augmentation-Statement of a melody in longer note values, often twice as slow as the original.
Diminution-A Renaissance and Baroque ornamentation which consists of the restatement of a melody in which the note values are shortened, usually by half.

Tempo-The speed of the rhythm of a composition.

Presto-A directive to perform the indicated passage of a composition very quickly.

Vivace-A directive to perform a certain passage of a composition in a lively or brisk manner.

Allegro-A fast tempo marking between Allegretto and Vivace.

Andante-A moderate tempo marking between Largo and Moderato. This tempo typically has between 76 and 108 beats per minute.

Adagio-A slow tempo marking between Largo and Andante.

Largo-A slow and solemn tempo marking, having between 40 and 60 beats per minute.

Grave-The slowest tempo in music.

semitone= halfstep

tetrachord- W W H