accidentals in an atonal piece?

i think this is the right place to ask this.

are there any "rules" for determining which enharmonic notation to use in an atonal piece? i'm trying of course to make it as easy to read as possible, but i feel like my being so well acquainted with the thing makes me not such a good judge of that...

i've looked at some Ives pieces for piano, briefly. i did notice that he'll tend to stick with, for example, only sharps in one measure/phrase, and natural a note when necessary. is this a good example?

any advice anyone can give for making a keyless piece easily readable would be much appreciated =]

Im pretty sure there are, but dont quote me on that.

I know when I write Atonal pieces and show them to my professor, he make sure that I spell the intervals the way they actually sound (for example not writing intervals that sounds like seconds but look like thirds on the page).

Other things he makes me check are if they are uniformly spelled (in other words, he makes me avoid writing enharmonic spellings in the same passage as a way to help out the performers)

Personally, I agree with my professor, I would write atonal music in a way that is the easiest to read. Because atonal music is hard to play in the first place and the last thing your performers want to see is a bunch of enharmonic notes and oddly spelled intervals.

Sharps when ascending, flats descending. Keep it consistent for short periods is good when necessary, but just because you have a D-Sharp in measure 1 doesn't mean you can't have an E-Flat in measure 3.

Look at it. If it looks awkward to you it'll look awkward to your performer.

Well, there aren't any "rules" per se, but it's certainly a good idea to keep the things Plutokat mentioned in mind.

A third aspect one might consider is voice-leading. A passage that features a pitch sequence that moves chromatically upwards is usually easier to read when spelt with sharps, whereas the same passage going downwards would generally be spelt with flats. This is so for two reasons. First, because we are used to this sort of spelling from the common practice idea of leading tones, i.e. the tones are chromatically "bent" in the direction of the following note with accidentals, to emphasize the direction of the sequence. Second, because this practice reduces the amount of natural signs you need to write, making the score less cluttered and thus easier to read.

And of course, the thing Plutokat mentioned about "writing the intervals as they sound" is also valid in a sequence of single notes, to make your contours more distinct. I.e. when you write the sequence "G-G#", you are writing an augmented unison and both noteheads are on the same vertical position, which gives a less direct visual impression of something that moves upwards than if you wrote "G-Ab". Notice that this conflicts with the general advice to use sharps when going chromatically upwards - which shows that there are many cases where you have to weigh different priorities against each other.

And really, those are just some rough guidelines one can keep in mind and there are countless examples of where composers used entirely different reasonings for their enharmonic spellings (or even no reasoning at all). The main point, in my opinion, should just be readability, which you should be able to judge for yourself. (As long as you are working in equal temperament of course. If you use other tuning systems it's an entirely different question.)

EDIT: I didn't see charliep's post until I had already posted, so I said some things again he already mentioned.

One other thing to consider... PLEASE don't write an Augmented Second (i.e. C-D#)... This goes back to voice leading. I guarantee you the performer will miss it at LEAST one time. So, unless you are being mean, or it is required for some ungodly harmonic reason (i.e. strict tone row... or sharps ascending, and flats descending... etc), avoid the aug. 2nd.... it's much more readable as a minor 3rd.

thanks, all of you. this is incredibly helpful. =]