The closest touchstone is likely the deceptively complex and delicately orchestrated ambient classical music of Stars of the Lid.  Willits and Sakamoto similarly present a symphony in slow motion.  Each song contains a different balance of warm, rounded timbres, lingering resonances and tasteful silence, but ultimately the entire album flows as a single unbroken idea.  Every track is equally essential.

Willits swirls each of Sakamoto's carefully chosen chords into a kaleidoscopic wind that ebbs and flows with pleasant whimsicality.  Each chord is played several long seconds after the previous, but the larger melody arc still presents itself with vibrant clarity, even at this glacial pacing.  Sakamoto is a master, and shows through his performance that he knows the meaning of every note in his compositions, which demonstrate a deeply sophisticated understanding of theory and harmony.  Due to its non-repetitive nature, the music never recedes to 'background' status like many ambient albums do.

The music grips me with intense nostalgic contemplation...  While listening, I am struck with the beauty of my endlessly fascinating surroundings, I feel the effects of my actions and how many turns life has taken, ponder how much I do not know.  It has a rainy, melancholic feeling, but equally represents the sound of reverence and wonderment at all things the cosmos.

In conclusion, if you have any appreciation at all for beautiful ambience and piano reveries, you must own this album now!  It's a monumental, deeply affecting album that will tug at your heartstrings immediately and never leave your memory.  "Ancient Future" is up there with the great classical compositions and the work of ambient masters like Steve Roach, and it's probably my favorite work of Sakamoto's, as well.