Overall Rating: 3.5 (of 5)
Circle Of Fifths - Major Scale Notes
Lesson page edited, for giving a better introduction and conveying the topic in a more lucid fashion : courtesy of a special friend.
The 12 tones used in Western Music can be arranged in a 'circle' (or cycle) of fifths. This arrangement of tones is often looked at as a circle of keys.
Arranging keys in this pattern is useful because it helps us see the 'closeness' of keys to each other. The closer any two keys are on the circle the more notes they share. For example C and G are adjacent to each other on the circle and the keys of C and G major share six out of seven notes. Keys directly across the circle differ greatly from each other. For example the keys of A and E are on opposite sides of the circle, they have only two notes in common (D) and (Ab/G#).
The ways sharps and flats are added to keys follows the circle of fifths. Each step along the wheel adds another sharp or flat to a key. Some of the most common movements from chord to chord in progressions also follow the cycle of fifths. In some songs what look like almost random chords at first become much easier to memorize when you see that the root movement of the chords follows the circle of fifths (actually, chords often travel backwards along the circle of fifths... moving backwards along the circle is moving in fourths... the circle of fifths can also be called the circle of fourths. It's a matter of moving clockwise or counterclockwise along the same circle.)
But this lesson is concerned with just one aspect of the circle of fifths... Using the circle in order to know what sharps (and flats) are in a given major key.
If you memorize a portion of the circle, a few details and a few rules, you can know what notes are sharped and flatted in any key.
A special note on enharmonics:
There's six keys that are called the enharmonic keys because each one has an enharmonic pair ( which means same note different names.) Those keys, paired enharmonically are Db/C# Gb/F# Cb/B. Almost nothing is written in C#, Cb, or F#. Composers almost always go with Db, Gb and B. So much so in fact that the keys of C# F# and Cb exist more in theory than in actual use. Why? Because if you just get rid of C# and F# then there are no keys which start on a sharp! And as for using the B instead of Cb... well, wouldn't it seem a little perverse to call something a Cb when you could just call it a B?