I've been trying to figure out the chord progression from the beginning of this Mussorgsky piece (orchestrated by Shostakovich, link below) and I'm just curious if I'm getting things right. The chords are the first three played by the strings within the first 15 seconds. Unfortunately I can't find sheet music for the orchestration, but I tried playing the chords by ear and from what I've transcribed, the chords are fifth-chords/power chords and the progression is I-III-VI. Does this sound correct to anyone else?
Here is the piece:
Power chords seem to be rare in classical and I think this is what gives it an exotic feel, and that is what piqued my interest for analyzing this piece.