> How many fingers are usually used simultaneously to depress keys when
> playing say the piano?  When playing the organ with pedals and manuals,
> I'd be inclined to suspect that the magic number is ~7... two feet, 5
> fingers.  Therefore, a key to execution difficulty is the max number of
> simultaneous keystrokes (if you will).  Music could be even scored for
> difficulty like that... choose a suitable number x>1.  Then the
> difficulty involved in playing something without error would be:
> 


I've played pieces on piano that have 8-9 fingers at a time plus
pedaling.  I've played pieces that have just 2 fingers and no pedal that
are much harder.  So, the number of mental concepts doesn't map directly
the number of appendages in use.  And let's not forget, hitting the
right notes is a bare beginning; usually the goal is to make music, not
to hit all the right notes and win some sort of points.

The muddying factor here is chunking.  Familiar chords or riffs will
seem like single mental chunks, not groups of individual notes.  A good
musician will have lots of chunks and so doesn't have to think as hard.
Note that no musician has ever been good without a lot of training --
they must be learning *something* during that time!

Overall, the music examples aren't overwhelming.  A consistent
alternative view is that many things are automatic, that high-level
thought is still restricted to a single stream, and in fact that most of
what people do is automatic.


-Lex