I received a question about how to practice octaves, ie. thumb on the lower
string and the 3rd finger on the upper string. Octaves are difficult because
the spacing between the thumb varies depending on where you are on the
fingerboard, and because the thumb moves at a faster rate than the 3rd finger
as you go up the fingerboard. There are hundreds of exercises, all of which
are useful. Below are some ideas that I have heard over the years:
1. The primary note in the octave is the lower note. This is the bass of
the "chord" and is the note that the listener tends to focus on. So you must
make sure your lower note is in tune. Practice ascending and descending
scales with your thumb only, keeping your other fingers in position on the
upper string, which is to reduce stress on the thumb. I would also practice
arpeggios with the thumb. Get used to how far the thumb must shift. On the
descending scale, lighten up your arm, otherwise you will tend to not shift
back far enough.
2. Always keep your non-playing fingers in position. There are many ways to
practice this, including playing major scales as you shift up one half-step
at a time. Another good exercise is to play one octave scales from thumb on
the lower string to the 3rd finger on the upper string, and then shift your
hand up to the next note in the scale degree, and play the scale again though
starting on the second note of the scale. For example, start with the thumb
on A on the D string and play an A Major Scale. Then shift the thumb to B on
the D string, and play the A Major Scale again, but starting and ending on B.
Then shift to C#, etc. Note how your finger configurations must change
depending on what scale degree you start on. This will help with intonation
in thumb position too.
3. Practice octaves by playing arpeggios in octaves as well as other
intervals like 4ths and 5ths. Get a sense of where your 3rd finger should
end up after the shift. Remember, your thumb is the primary note and that
your 3rd must adjust to it, not the other way around. The key is to have a
destination in mind when you play octaves. For instance, if I am playing an
ascending scale in octaves, like in the first movement of the Dvorak,
determine the beginning and ending spacing of your hand. Then, as you go up,
shoot for that spacing at the end of the scale. You may even break up this
long scale into a few destinations notes. But lead with the thumb.
4. Practice octaves by slowly increasing the interval you are shifting. For
example, start on A and shift to B-flat. Shift back to A. Do this until you
get it in tune. Then shift from A to B-natural. Then A to C. And so on.
5. You can play scales with your third finger alone, keeping the thumb
silent. You can play broken octave scales ie. D-D-E-E-F-F. There are tons
of [Miscellaneous] exercises.
6. Some teachers recommend bunching your non-playing fingers against your
3rd finger to give it added support. This may work, but it increases tension
in the hand and can cause cramps. So I am not sold on it.
7. If you are playing thumb position in the lower position zone, ie. along
the neck of the cello, be sure to bend your first thumb joint in order to
maintain the thumb perpendicular to the string.
8. Keep your wrist perpendicular to the fingerboard as you ascend. To do
this, you must lower your entire arm, adjusting your entire body position.
9. Practice octaves in "single line studies," where you sound just one line
while only lightly fingering the other, progressing to breaking the double
stop from the bottom, then to breaking from the top.
10. Be sure to keep your wrist flat to prevent carpal tunnel syndrome. I
didn't while practicing Popper #13 and ended up being incapacitated for