Virginia Knight:

>a) pitch memory.  ...
>
>b) working out the interval of the next note from a previous note (usually
>but not always the one immediately preceding)
>
>c) relating the notes to a key When you've really learnt the piece
>thoroughly all of this is replaced by
>
>d) just knowing how the piece goes so that when given a starting note you
>can sing it without consciously working it out as you go along.
>
>With an atonal piece of course method c) fails completely.

I hate to say this, but it also fails in some tonal music (solely from
the point of view of the performer).  I just had the great joy of singing
Ravel's Trois Chansons for a cappella chorus.  This group has above-average
sight readers.  The big problem came in the third movement, "Ronde," which
is frequently in two different keys at once.  Some of those pitches cannot
be gotten with method (c).  Or at least we didn't manage it.  It was a
combo of (a), (b), and - finally - (d), just as for Nasty Old Atonal Music.
The pieces are, however, gorgeous.

Steve Schwartz