Modes, key signatures, and tonic

[Bespinben]

I'm working on arranging "Ragged Mountain" from PMD Gates to Infinity, and it's clearly in Eb mixolydian. What I have trouble with is that I am reluctant to write the key signature as 4 flats, because it could easily be confused with Ab major. I'd much rather just have a Db accidental whenever the piece calls for one. D natural is used frequently past m. 20, to boot. Is there some sort of notational convention for this that mandates one or the other, or is this one of those "whatever floats your boat" things?

Here's the PDF of what I have so far, if it's needed:
https://dl.dropboxusercontent.com/u/35209091/PMD3DS%20-%20Ragged%20Mountain.pdf

[Sebastian]

I'd love to help, but, alas I'm terrible at Key Sigs

[Olimar12345]

I'd just use the key of Eb and write out the Db's. Sometimes others will use the key sig change, but then it questions what tonic is. It's a preference thing.

[Bespinben]

Ok! Good to know. I like keeping the tonic clear so that when I see an accidental I can have gist for what it's function will be in relation to the tonic when I'm playing through a piece. Helps me hear the note before I play it, so to speak.

(Though, I digress - I'll still always want Song of Time in D Dorian with key of C. Consistency *shot*! XD)

[Jompa]

You're not supposed to base the signature on modes. When it comes to key it's either major or minor, so something in lets say A-dorian should be notated with no sharps and no flats.

[FierceDeity]

You're not supposed to base the signature on modes.

It's a preference thing.

It really is up to preference. The only people reading it who give a fuck about accurate tonic representation will have some basis in theory, and those people should be able to realize it's not the ionian or aeolian mode that key signature typically represents. Many players consider it easier to read in mode-specific key signatures, so it really doesn't make sense to call that method wrong when the pitch center should be discernible from the harmonic progression itself.

[mikey]

maybe it's just me but if it's in Eb I prefer to have it in Eb with the various accidentals added in to make it mixolydian

[Jompa]

It really is up to preference. The only people reading it who give a fuck about accurate tonic representation will have some basis in theory, and those people should be able to realize it's not the ionian or aeolian mode that key signature typically represents. Many players consider it easier to read in mode-specific key signatures, so it really doesn't make sense to call that method wrong when the pitch center should be discernible from the harmonic progression itself.

Look, stuff's often mistakenly written in mode-specific key signatures, but it's still wrong. No point philosophying about it.

[mikey]

I think it's PHILOSOPHIZING

[Olimar12345]

Look, stuff's often mistakenly written in mode-specific key signatures, but it's still wrong. No point philosophying about it.

I am agreeing with you that the way you specified to do it is correct and makes the most sense from a theorists view. What I was saying was that sometimes music is written with keys that match the accidentals used in modes. People sometimes do it. From a theorists standpoint it is odd and seems incorrect, but there's usually a good reason for writing it that way if they choose to do so.

[FierceDeity]

Yes, every jazz composer who writes D Dorian with no sharps or flats in the key signature is "wrong" -_-

...except that the current rules of theory in this area are loosely defined at best, and even the definitions you're using arise from "common" practice. Rules of theory are made to reflect this convention, and to facilitate practicality, so perhaps we should be a little more "philosophical" (if that's how you describe any thinking apart from arbitrarily following rules made only for the convenience of analysts) in these considerations. The rules are great and all, but are primarily just there as a template, and for you to know when and why you're breaking them.

As for whether it's "correct" to write it this way, I have a few professors who might disagree with you.