ref:I recently bought "Hanging Gardens" by The Necks and
> I love it> So now I'm curious for their other
albums? Which are recommended

Likewise I stumbled across Hanging Gardens and loved it, can also recommend Aether from 2001. Similarly its a single track which clocks in at around an hour. Progress is equally unhurried and quite magnificent for this fact.
Would be interested to hear more concrete info on the overdub front. I seem to recall a review claiming no overdubs had been used, the album being recorded live in studio. Or maybe I dreamt that.
bruno