The song starts off with a short and light, simple, yet beautiful melody before it gets disrupted loud thunder sounds along with the lower base-like tones on the piano. After that, it continues the melody at the start, before getting interrupted again by the thunder sounds.
It kind of sounds like a cinematic piece of work that tells a story about either light and darkness, or peaceful weather and a heavy volatile storm, if that makes sense?
I'm sorry this is so vague, I hear it a long time ago. But if it helps, then I heard it as a part of a Rhythmic Gymnastic CD filled with 1:30 minute-long songs that were only played by instruments (no vocals/voices).