I spent a good bit of time this past weekend entering an old piece of mine into Finale. This activity always makes me think about some of the decisions I made during the composition of the piece. In this particular work (Radiant Geometries, a fanfare for two trumpets) the issue that kept coming up was the spelling of pitch.
"Spelling" is the seemingly trivial decision about what note to write down to indicate a particular pitch. And the decision is usually so trivial that no thought need be given it. But that's not always the case. For a composer of functionally tonal music, the spelling of the notes of a harmony or a melody is often determined by the function of a note in that chord or melody. For example if a chord is leading towards A natural, the note a semi-tone below A in the chord generally will be spelled "G#", though it could also be spelled "Ab".
The spelling of pitches also affects how they are played in tonal music. Our G# would likely be pushed a little higher by string players and singers, in order to emphasize its leading tone function.
In a pantonal context, the spelling issue comes down largely to performability. My principal composition teacher, William Hibbard, inculcated two spelling principles in me. One, spell in sharps as a general rule, especially if you are writing music for strings. Sharps are more, as it were, natural for string players because the open strings are tuned to notes that are the home pitches in keys with sharps in the key signature. The other general rule is to spell tonally, even if the context isn't tonal.
Intervals are designated with two words. An adjective refers to the particular "width" of the interval, and a noun communicates the distance between the letter names of the notes involved. The interval between notes with the letter names "C" and "D" is going to be a "second" of some kind, while a "C" and another "C" is a unison, a "C" and an "E" a third, and so on. C natural and D natural are two semitones apart and are refered to as a Major second. Make the C a C# and you have a minor second. Raise the D to a D# and you are back to a Major second. If you then lower the C# to C nat, you have an augmented second (C/D#), an interval that is generally avoided in tonal music, mostly for intonation reasons. So, in non-tonal music you would most likely change the "D#" to an "Eb", with the result being a user friendly minor third.
These issues came up in composing Radiant Geometries, and they rear their head again in the data entry, with the addition of transposing for the parts. Trumpets are generally transposing instruments (don't ask) and Bb trumpets (the most common kind; really, don't ask) have parts that are written a Major second above the sounding pitch. This can lead to some spelling issues, the most interesting of which are B# and E#. B and C are only one semitone apart, as are E and F, unlike all the other letter pairs, which are two semitones apart. Therefore, B# and C natural (as well as E# and F natural) are the "same" notes (apart from the leading tone issues mentioned above, which generally don't come into play in a pantonal context).
When an A# or D# appears in the untransposed score, the software prints B# and E# in the parts, and nobody wants to play those notes unless they absolutely have to. C and F are much easier. So then you have to decide whether to renotate the line to avoid those spellings while still following the rule to spell tonally, or ask the trumpeter to play the offending notes in an unusual spelling in a fast piece.
What's a mother to do?