Key sigs for Octatonic Scales?

[InsigTurtle]

So, the song I'm transcribing uses an octatonic scale. The scale in question has G,A,Bb,C,Db,Eb,Fb and Gb. Since there's nothing mentioning which key signature to use in octatonic scales in my advanced rudiments, which key signature should i use? I don't know if this will help, but the key later changes to Eb harmonic minor.

[Jompa]

This is an answer people like Ricky would hate, but it's what I think:
A key signature is assigned out of what the tonic is and wether it's minor or major.
You didn't mention what the tonic is in the song, but I'm guessing G since that's the note you started on. And the third is minor.
So the tonic chord is G minor, and going by my definition on how to use key signatures, you should use the key signature G minor with two flats.

Might worth mentioning that a scale used in the song doesn't really mean much - even if it is used regularly, there might just be irregularities from the normal minor scale or some mode. Actually that's more likely.
But I don't know what song you're talking about, so I wouldn't know.

[Olimar12345]

Leaving it in open key is also acceptable(I'd prefer). Actually, I hardly ever see key sigs in music like that.

[Ricky]

Ok, the option Jompa would hate: If possible (that is if your notation program can do that) is to make an custom key signature, in this case with B, D, E, F & G flatted. Another option could be trying to find the closest regular key signature. Basically those flats: B, E, A, D, G, C, F. And the A and C are to be naturalized. Assigning a key signature of major or minor by relating it to the tonic like Jompa suggests doesn't make much sense when looking at from a theoretical perspective. For example if I would want C Mixolydian the logical thing would be to use the key signature of one flat (Bb) but Jompa instead used the key signature of C major and flats the 7th each time by hand. Either way, do whatever you feel is better.

[Jompa]

@Ricky: If he flattens the G, he's flattening the tonic.

@Rosabellis:
You should really find out if this is the case: (because this could be important):

Might worth mentioning that a scale used in the song doesn't really mean much - even if it is used regularly, there might just be irregularities from the normal minor scale or some mode. Actually that's more likely.

If so, and it becomes a question about what mode it is in (rather then simply minor or major (cause that's where me and Ricky actually agree, ofc)), then your choice of key signature would end up depending on wether you believe in my definition, or Ricky's.

If it doesn't end up being the case, you'll also have to decide who you think is right:
I ofc think you should go for G minor either way - out of both the probability that the quote above is the case (and that it's G minor regardless of mode), and out of the chance that it's not the case, still leaving you with the tonic being G with a minor third.
If you think Ricky's right, you probably wanna go for a no-key signature, because Ricky's example didn't really work, but in his view any key signature is ok as long as it's clean when it comes to the loose accidentals. He did tell you to do whatever you feel is best.

If you need any more help, could you perhaps tell us what song it is?

[InsigTurtle]

Well, I guess maybe I should let you guys judge...
https://www.dropbox.com/s/xr9gxb4s4771t36/sealruinpit.mus
The octatonic scale is only used in the first 6 measures, before it goes into C Phrygian, I believe? It could be an irregularity, I guess...

[Ricky]

@Ricky: If he flattens the G, he's flattening the tonic.

Ah, my bad. I didn't notice my mistake.

Maybe rewriting things in terms of sharps would be better, I don't know.

but in his view any key signature is ok as long as it's clean when it comes to the loose accidentals.

Not necessarily just to lose accidentals, more a case of finding a key signature that suits the music.

[JDMEK5]

I'm gonna make a "Jompa vs. Ricky - Theory Debate" thread one of these days....

As for where I stand on the subject, I primarily agree with Jompa, but Olimar's solution is perfectly acceptable as well.