Essentials of Music Theory: Elementary — Story, Setting & Ideas

Sound is the effect produced by propagated atmospheric waves which affect the sense of hearing. Irregular impulses, propagated through the air, produce noise. Regular impulses produce musical -tone-.

The duration of tone is indicated by symbols called -notes-. Following is a list of notes:--

[Double whole note] or [Breve] Double whole note or -Breve-.

[Semibreve] Whole note or -Semibreve-.

[Minim] Half note or -Minim-.

[Quarter] Quarter note or -Crotchet-.

[Eighth] Eighth note or -Quaver-.

[Semiquaver] Sixteenth note or -Semiquaver-.

[Demisemiquaver] Thirty-second note or -Demisemiquaver-.

Occasionally the sixty-fourth note ([Sixty-fourth note]) is used. Following is a table of the relative value of notes:--

The -breve- or double whole note is not given in this table as it is but seldom used. The value of it is twice the whole note, four times the half, etc.

The whole note is represented by an open oval; the half, by an open oval and stem; the quarter, by a closed head and stem; the eighth note is the same as the quarter with a flag; the sixteenth, the same with two flags; the thirty-second, the same with three flags. As is seen in the table, the eighth, sixteenth and thirty-second notes are often grouped when more than one occurs in succession.

Suspension of tone is indicated by symbols called -rests-. Each note has its equivalent rest. Following is a list of rests:--

[Double whole rest] Double whole rest. [Whole rest] Whole rest. [Half rest] Half rest. [Quarter rest] Quarter rest. [Eighth rest] Eighth rest. [Sixteenth rest] Sixteenth rest. [Thirty-second rest] Thirty-second rest.

The rate of vibration is called -pitch-. Rapid vibrations produce "high" (shrill) tones. Slow vibrations produce "low" tones. More complete information on sound, tone and pitch is given later under the heading "Acoustics."

The notes are written on the staff which consists of five horizontal lines together with their spaces. The duration of a tone is determined by the note used; the pitch, by the note's position on the staff.

A dot placed after a note or rest adds one half its value. A "tie" is a curved line connecting two notes of the same pitch. Examples of dots and ties:--

[Semibreve with Augmentation dot] equals [Semibreve tied with Minim] or 1 + 1/2.

[dotted half note] equals [half note tied to quarter note] or 1/2 + 1/4. [dotted quarter note] equals [quarter note tied to eight note] or 1/4 + 1/8. etc., etc.

A double dot adds one half and one fourth its value, thus:--

[double dotted whole note] equals [tied notes; tied whole, half and quarter note] or 1 + 1/2 + 1/4. [double dotted half note] equals [tied notes; tied half, quarter and eighth note] or 1/2 + 1/4 + 1/8. [double dotted quarter note] equals [music symbol; tied quarter, eighth and sixteenth notes] or 1/4 + 1/8 + 1/16. etc., etc.

Bars are lines drawn vertically across the staff dividing music into -measures-. The contents of the measure is determined by the fraction at the beginning. The denominator of the fraction shows the kind of notes, and the numerator, the number of that kind contained in a measure. Each measure must contain the number and kind of notes or rests designated by the fraction, or their equivalents.

-Artificial groups- are groups of notes played and summed in other than their fractional value. The most common artificial groups are the -triplet- and -sextuplet-. A triplet is a group of three notes played in the time and summed in the value of two of its own kind. A sextuplet is a group of six notes played in the time and summed in the value of four of its own kind. A group of five notes is played in the time and summed in the value of four of its own kind. A group of seven notes is played in the time and summed in the value of six of its own kind. Occasionally a group of two notes occurs. This group differs from other artificial groups inasmuch as it is played more slowly than the tempo notes. A group of two notes is played in the time and summed in the value of three of its own kind. Artificial groups are designated by a curved line over or under the notes with a figure showing the kind of group, thus:--

triplet ] sextuplet ] group of two notes ]