This week, we're going to look at Pattern 3, the finger pattern used to play the keys on the left side of the Circle of Fifths (Bb Major through Db Major). Playing these keys is in some ways easier than playing the keys on the right side.
Before we go into fingering for these scales, let's sit at the piano and look at the black keys. They come, as you know, in alternating sets of 2 and 3. We typically use Fingers 2 and 3 on Db and Eb, and Fingers 2,3, and 4 on Gb, Ab, and Bb.
Play the black notes using these fingers. The R.H. uses Finger 2 on Db and Gb. The L.H. uses Finger 3 on Db and 4 on Gb.
Right Hand: Our goal for the R.H. is fairly simple, when you play the black keys ensure that you're playing them using the R.H. fingers indicated. Typically, this results in the thumb playing C and F. In the case of Gb Major, the thumb plays Cb (also known as B) and F.
Left Hand: With the L.H., when you play Gb, your thumb will play Cb and F just as it does in the R.H. The L.H. for Db Major poses no problem either. You'll find yourself using Finger 4 on Fa.
Make a note of this because this is the pattern that we'll follow for the other keys: Finger 4 on Fa. It just so happens, that Fa - or the new flat in the key of Db Major - is Gb, which is played with Finger 4, in any case.
For the L.H. for Ab, you'll want to play Fa (or Db) with Finger 4 rather than Finger 3 so you play Hi Do with the same finger as you played Do: Finger 3. You could, of course, use Finger 4 on Ti (G), and you'd still be able to use Finger 3 on High Do. But it's easier to remember to use Finger on 4 on Fa, the new flat.
To play Fa - or the new flat with Finger 4 - for the keys of Bb Major and Eb Major, the starting finger for the L.H. for each of these keys has to be Finger 3. Now, you could start on the finger typically used for these notes: Finger 2. But in this case you'll have to remember to use Finger 4 on Mi so that you end on High Do with Finger 2.
It seems easier to just remember to play Fa with Finger 4 for the keys Bb through Db. You have a single pattern for the L.H. that applies to every key except Gb Major (where the thumb quite naturally falls on Fa). For the keys of Bb and Eb, your starting finger is 3 rather than 2 - again, quite easy to remember.