PENTATONIC is derived from the Latin word ''PENTA" (meaning five). Pentatonic scales are FIVE note scales. They are one of the oldest and most widespread scales in common usage. They are thought to have Mongolian and Japanese origins.
There are two types of commonly used five-note Pentatonic Scales: Major and Minor. A third scale, an ALTERED Pentatonic (or six-note Blues scale), completes this popular group of improvisational scale forms.
The Major Pentatonic Scale is a select pattern of major scale notes – a major scale with the 4th and 7th degrees left out, and may be used interchangeable with the Major Scale of the same key signature.
The Major Pentatonic Scale (no 7th) may be played over Dominant chords, chords with a lowered seventh (13th 5b7), and works equally well against Major Seventh chords, chords with a natural seventh (1357). The Major Pentatonic Scale emphasizes the 6th and 9th degrees, and creates the traditional "sweet-country'' sound.
The guitar, tuned to ''standard pitch'' (E A D G B E), is an expanded G MAJOR PENTATONIC SCALE.
The PENTATONIC MINOR scale is a five-note scale with a Minor Third. It is a NATURAL MINOR scale with the 2nd and 6th degree left out. The Pentatonic Minor scale may be substituted for a Melodic Minor scale.
The BLUES scale is a Pentatonic Minor scale with a raised 4th degree. This one additional note adds an interesting ' Bluesy' sound and is used extensively in Rock, Blues and Jazz improvisation.
These two Pentatonic scales and the Blues scales share the same chordal relationship as diatonic major and minor scales. They may be played over an entire chord progression – it is not necessary to change scales when the chord changes.
When played from a CLOSED POSITION, these scales, like the major scale forms, move chromatically.
Jack R. Baker