Beginners Music Theory/Elements of Rhythm

Elements of rhythm

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Rhythm is a general term that refers to the time aspect of music. The duration of each note is determined by the note head and stem. The note head is the round part of the note and it can by filled in or hollow. The stem is the vertical line which stems from the note head. All notes have both of these parts with the exception of the whole note and the breve.

Beat is the basic pulse of music. This can be found by tapping one's foot to music; the beat falls in line with the foot hitting the floor. The rate at which beats occur is called tempo. The time signature of music indicates the number of beats that will occur in each measure and what note value will represent the beat. This is expressed with two vertically stacked numbers with the number on top indicating the number of beats per measure and the number on bottom indicating what note value represents the beat.

The whole note is so named because in the most common time signature, one whole note lasts the entire measure. All other note values are named for the fraction of a whole note that they represent. Therefore, a whole note lasts twice as long as a half note and a half note lasts twice as long as a quarter note.

An easy way to learn which bottom number of a time signature represents which note values is to think of the number as a division of the whole note. In 4/4, the bottom number is 4, which means that 4 of that note fit inside of a whole note. 4 quarter notes go into a whole note, so in 4/4 the beat unit must be quarter notes.

Note Value Table
Note Value name Note Value Description (American Term/British Term) Equivalence in terms of American dollars
Whole Note/Semibreve hollow head 1 dollar
Half Note/Minim hollow head with a stem attached to the right of it 50 cents
Quarter Note/Crotchet a half note, but with a solid head 25 cents
Eighth Note/Quaver a quarter note with a flag facing downwards and rightwards attached to its stem 12.5 cents
Sixteenth Note/Semiquaver a quarter note with two flags at different positions on the stem 6.25 cents
         
Whole Note Half Note Quarter Note Eighth Note Sixteenth Note
Rest Value Table
Rest Value name Rest Value Description (American Term/British Term)
Whole rest/Semibreve rest bar attached to the underside of the line above the middle
Half rest/Minim rest short bar placed on top of the middle line
Quarter rest/Crotchet rest squiggly backward 's' spanning three lines
Eighth rest/Quaver rest figure 'seven' with a hook facing upward attached to the uppermost end, touching the line above the middle with its head
Sixteenth rest/Semiquaver rest two eighth notes attached, one above the other and atop its head, and spanning four lines, starting at the bottom.
         
Whole rest Half rest Quarter rest Eighth rest Sixteenth rest

Dotting and Double-Dotting

A dot, placed to the immediate right of the notehead, increases its time-value by half; thus a minim (half note) (which is equivalent to two crotchets (quarter notes)) followed by a dot (which in this case is equivalent to a further crotchet (quarter note)) is equivalent to three crotchets (quarter notes), while a dotted crotchet (dotted quarter note) is equivalent to three quavers (eighth notes) and a dotted quaver (dotted eighth note) is equivalent to three semiquavers (sixteenth notes)). If the notehead is located in a space, the dot is placed in that same space. If the notehead is on a line, the dot is placed in the space just above the line. Exceptions sometimes have to be made if several dotted notes share a single stem. A dot placed after a rest or note is called an augmentation dot. Imagine, if you will, a note with a dot to the right of it.
A second dot, placed to the immediate right of the first dot, increases the original undotted time-value by a further quarter. Another way of thinking about the second dot is that it adds the note equivalent to half the note added by the first dot. So, for example, a minim (half note) (equivalent to four quavers (eighth notes)) followed by one dot (equivalent to two quavers (eighth notes)) followed by a second dot (equivalent to one quaver (eighth note)) is equivalent, in total, to seven quavers (eighth notes).

A triple-dotted note is a note with three dots written after it; its duration is 1 7/8 times (1 + 1/2 + 1/4 + 1/8) its basic note value. Use of a triple-dotted note value is not common in the Baroque and Classical periods, but quite common in the music of Richard Wagner and Anton Bruckner, especially in their brass parts

Dots after rests increase their time-value in the same way as dots after notes.

Triplets

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An example of what eighth note triplets look like on a staff compared to normal eighth notes

It is also possible to divide a note into 3 equal parts rather than 2 equal parts. A quarter note can be divided into 2 eighth notes (where each eighth note is half as long as the quarter note), but it can also be divided into 3 eighth note triplets (where each eighth note is a third as long as the quarter note). In order to notate this, a 3 is placed on the beam of the triplets to indicate that this is a grouping of 3. Both 2 eighth notes and 3 eighth note triplets take up the same amount of time, 1 quarter note. This triplet division can be done with other note values as well, a half note can either be split into 2 quarter notes or 3 quarter note triplets (in the absence of a beam, a bracket is placed over the 3 quarter note triplets with a "3" on it to indicate that it is a triplet). It's important to remember that creating triplets is dividing the note the same way it would divide in two, so you always notate a triplet as a subdivision of the note (a half note isn't split into 3 half-note triplets, it's split into 3 quarter note triplets, and those 3 triplets combined are as long as a half note).