Changes

In traditional Western music, the '''key''' is the tonal center of a composition.  The choice of key determines which of the other notes in the scale will be considered "natural".

In traditional Western music, the '''key''' is the tonal center of a composition.  The choice of key determines which of the other notes in the scale will be considered "natural".

The Western scale divides the octave into twelve [[note]]s (plus the [[octave]], at double the [[frequency]] of the lowest note).  Any given key uses eight of these, or seven plus the octave, from which the [[composer]] can construct [[melody|melodies]] and [[harmony|harmonies]].  Since many times the judicious use of the other five notes, also known as chromaticism, will make the music more compelling, we have notation devices to indicate when they are used instead of their natural counterparts. A piece of music will also often change keys at various times, known as modulation.  This is usually done by moving to a closely related key, that is, one whose [[key signature]] only differs by one sharp or flat in either direction.  An easy way to find which keys are related in this way is to follow the [[circle of fifths]].  

The Western scale divides the octave into twelve notes (plus the [[octave]], at double the [[frequency]] of the lowest note).  Any given key uses eight of these, or seven plus the octave, from which the [[composer]] can construct [[melody|melodies]] and [[harmony|harmonies]].  Since many times the judicious use of the other five notes, also known as chromaticism, will make the music more compelling, we have notation devices to indicate when they are used instead of their natural counterparts. A piece of music will also often change keys at various times, known as modulation.  This is usually done by moving to a closely related key, that is, one whose [[key signature]] only differs by one sharp or flat in either direction.  An easy way to find which keys are related in this way is to follow the circle of fifths.  

The notes used in the key of C major (corresponding to the white notes on the piano) are C, D, E, F, G, A, B and C.  When sung or played, these are often referred to by their respective names ''do'', ''re'', ''mi'', ''fa'', ''so'', ''la'' ''ti'', and ''do''.

The notes used in the key of C major (corresponding to the white notes on the piano) are C, D, E, F, G, A, B and C.  When sung or played, these are often referred to by their respective names ''do'', ''re'', ''mi'', ''fa'', ''so'', ''la'' ''ti'', and ''do''.

In the late nineteenth century, composers such as [[Richard Wagner]], [[Hugo Wolf]], and [[Richard Strauss]] began to use extreme chromaticism and modulations to distantly related keys for a heightened expressive affect. In the [[Twentieth Century period (music)|twentieth century]], this trend developed to the point where the listener's impression of a tonal center became weak or even irrelevant, leading to [[atonal]] music. [[Arnold Schoenberg|Arnold Schönberg]] eventually attempted to create a new set of rules to replace tonality, resulting in [[twelve tone]] music.

In the late nineteenth century, composers such as [[Richard Wagner]], [[Hugo Wolf]], and [[Richard Strauss]] began to use extreme chromaticism and modulations to distantly related keys for a heightened expressive affect. In the [[Twentieth Century period (music)|twentieth century]], this trend developed to the point where the listener's impression of a tonal center became weak or even irrelevant, leading to [[atonal music]]. [[Arnold Schoenberg|Arnold Schönberg]] eventually attempted to create a new set of rules to replace tonality, resulting in twelve tone music.

Many styles, or genres, of music are quite recognizable by the type of key structure they employ.

Many styles, or genres, of music are quite recognizable by the type of key structure they employ.