A scale is simply a series of
notes played from a starting point, progressing in ascending order, and ending
one octave from the starting point. It can also continue into the next octave
or descend back to the starting point. Most scales move from one note to the
next by either a whole step or a half step. The thing that distinguishes one
scale from another is the exact sequence of whole and half steps.
Probably the simplest scale to
learn and understand is the chromatic scale. A chromatic scale can start on any
note and ascends one half step at a time. You play all 12 notes before you end
an octave above the starting point. An easy way to play this on the guitar is
to start with the low E string (6th string) and play it open, 1st fret, 2nd
fret, 3rd fret, etc. continuing to the 12th fret. You have just played the
notes E, F, F#, G, G#, A, A#, B, C, C#, D, D#, and E. A more efficient way to
play this on the guitar would be to play only up to the 4th fret on the E
string, change to the A string (5th string) and play up to the 4th fret, then
change to the D string (4th string) and play up to the 2nd fret. The best way
to finger this with your left hand is to play in 1st position. This means using
your 1st finger at the 1st fret, 2nd finger at the 2nd fret, 3rd finger at the
3rd fret, and 4th finger at the 4th fret. This way your left hand is not
sliding up or down the neck (changing positions).
The chromatic scale is not
particularly useful in terms of composition or harmony but can be a great
coordination exercise if you combine the right hand technique of alternating
picking, either with a flat pick alternating down strokes with up strokes, or
using two fingers alternating the index finger with the middle finger. See the
diagram in the article The
Chromatic Scale in the Exercises
section.
A close relative to the chromatic
scale is the whole-tone scale. This scale would be a sequence of whole steps,
which would only have six different notes in it (E, F#, G#, A#, C, D for
example) and is even less useful than the chromatic scale. See the additional
articles about other specific scales and modes.