The tonal center is ambiguous. You can play C Lydian or B Phrygian. The progression, though, is Lydian. If you don't know C Lydian, play the scale shapes for E Minor. They have the same notes. Keep in mind that C is the root, and F# is the signature note of C Lydian. If you stress the F#, in other words, you will get that erie -- but beautiful - tonality characteristic of Lydian.

Video image derived from an awesome photo by Zoriah.
Photo: flickr.com/photos/zoriah/4624435856/
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