key center

I did try the search, but I didn't find anything related. In an old post, in a different forum @BassCliff made the following statement: How does this really work? I can't visualize playing the same 'pattern' (different strings and/or a few frets apart, I get that) and sounding in a...

I've written this chord progression which I like, but I'm having trouble with arranging and writing around it since I'm having trouble with not knowing what the key centres are. Any help is appreciated! The chords are: G#m9/F# - Gmaj9/F# - Cm9/G - Em9/D - G#m9/D# - then go backwards through...