Music Theory
Intervals
Chromatic Scales
Diatonic Scales
So far, we have been able to relate half step musical intervals with
consecutive keys on a keyboard. We also studied diatonic scales
that have seven, not twelve, notes per octave, and studied the circle
of fifths that indicates how many sharps or flats to use when placing a
major or minor scale in a certain key.
Still, there is one more step to go. You want to know which seven
of the twelve notes per octave to use when playing a song. There are
two ways to do that.
Rely on the the Key Signature
f you are reading music, the key signature will narrow down all
this for you. For each of the seven letter names A through G, it
tells you which of those notes should be made sharp or flat. You
still have seven total, but some have been made sharp or flat.
but this produces a list of the seven notes of the twelve possibilities
per octave that you will use. If you use this method, then just
skip the remainder of this web page.
Determine Sharps or Flats using the
Circle of Fifths
f you are not reading music, you determine two things:
(1) the mode of your song
(major or minor, most likely) and
(2) the key in which to play
the song
Once you determined those two things, you can do one of two things:
(1) Start your scale on the note of the key you are playing in, and
knowing the interval spacing in the scale, determine the other six
notes to use, or
(2) Refer to the circle of fifths article under Music Theory to see how
many sharps or flats are required for the key you selected, and then
assign those sharps or flats to notes A through G, based on the circle
of fifths rule for assigning sharps or flats.
How to Assign Sharps
The rule for assigning the right number of sharps or flats goes like
this.
F is the first note to be made sharp. After that, ascend through
the circle of fifths to assign additional sharps, till you have reached
the desired number of sharps.
How to Assign Flats
The rule for assigning flats is:
B-flat is the first note to be made flat. After that, descend
through the circle of fifths to assign additional flats, till you have
reached the desired number of flats.
Example of a Sharp Scale
For example, if you decide to play a song written in a major scale, and
you want that song in the key of E, refer to the circle of fifths chart
for major scales, and see that E major has four sharps. Then,
assign the first sharp to F, the second to C, the third to G, and the
fourth to D. So, the E major scale begins on E and uses:
E, F#, G#, A, B, C#, D#, E
Example of a Flat Scale
If you decide to play a song written in a minor scale, and you
want
that song in the key of g minor, refer to the circle of fifths chart
for minor scales, and see that g minor has wo flats. Then, assign
the first flat to B, and the second to E. So,
the g minor scale begins on G and uses:
G, A, B-flat, C, D, E-flat, F, G
After either procedure, you know the seven notes that you need to play
the song..... unless there are what are called 'accidentals' that don't
belong in the key that the composer threw in for good measure.
Anyway, now you should find those notes on your instrument.
Now that you know how to place a major or minor scale in a particular
key, using the right number of sharps or flats, you can begin to look
at chords to play along with your melody.