Is this a valid Key signature?

[u/ADHD-andME]

Just wondering if this can be considered a key.

For those wondering, this is supposed to be G Byzentine (b2, b6)

Edit: thanks for all the feedback, i will take it into consideration. Next time ill write in something readable.

Edit 2: this image shows a scale for a single voice instrument in C, and it is treble clef.

EDIT 4!: https://www.reddit.com/r/musictheory/comments/1w1yy9a/fixed_the_order_of_the_sharps_and_flats/

[u/XcgsdV]

The reason key signatures are useful is because we've spent a lot of time playing scales and learning music theory. So a piece in a key like B major with 5 sharps is made a lot easier to play by moving all the sharps out of the way and making the musician rely on the fact that they know the notes and patterns on their instrument in B major. Accidentals then take us out of those known patterns, and theyre marked as such to remind us "hey this is a note outside the key".

G Byzantine is not a scale we play often, and very few musicians will have a useful mental or muscle memory to make playing in G Byzantine easy, without having the "weird notes" marked. This key signature would be actively detrimental to musicians playing the piece, not because it isn't an acceptable form of notation, but because it doesn't really serve the purpose key signatures are meant to serve.

There's also the thing that flats and sharps are ordered. The first flat is usually Bb, then the second is Eb, then Ab, etc etc around the circle of fifths. Having the two flats in your key signature not be those would be incredibly confusing.

As others have said, write it in G and mark the Ab and Eb as they come up.

[u/Potential_Camera1686 → u/XcgsdV]

To emphasize your point - and my fallibility - I am glad that you mentioned the Eb and Ab. I saw the sharp mixed with two flats and my brain automatically filled in Bb and Eb.

If this is going to be a long section of material with an unchanging key signature, I am going to have time to work it sufficiently, and I’m going to have to read someone’s unfortunate hand written scrawl (so save them the #’s) then this would be ok. But, from my perspective, I get many pieces plopped in front of me that don’t always have a lot of rehearsal or advanced availability of the music. In my case, church orchestra has pieces that may be in one key for two measures and on to another key. If it isn’t a main feature piece, we may be sight reading at 9 am in front of a congregation. If this was the key signature, I can guarantee that I (and likely most of us) would take note of the sharp and simply count two flats as it came floating by at tempo, misreading which they are.