Đường Hầm Trong Sương
Ultra-slow ambient piano at ~42 BPM, male vocals optional as distant airy hums; only low and mid registers of the piano, long reverberant tones, sparse voicings, and gentle evolving drones. Static harmony with subtle voicing shifts, no melodic build or emotional arc, like a foggy underground station at night; mix bathes everything in soft reverb and distant room tone., ambient