Fleetwood Mac; Albatross (Blend) by Keith Fullerton Whitman

Not a "Greatest Hit" per se, but easily my favorite (early) Mac song, edited across multiple versions & fidelities to play somewhat seamlessly for over 2 hours, with the mix slowly being eroded by a cavernous echo that is being gated by the dynamics of the dry signal.

EDIT, 06/17/18. I was taken aback by Danny Kirwan's passing a few days after I originally posted this. One of my all-time favorites, esp. within the context of both this lineup of Mac & this particular song; the original studio session which starts off the proceedings here was his first recorded appearance with the band!

I've taken the original premise & fleshed it out a bit further, so that it can be put it to rest; this revised version uses the following versions of "Albatross" in a program that loops three times; almost entirely dry, then slowly fading in the reverb signal, finally slowly fading out the dry signal:

UK Mono 7"
Stereo from "Pious Bird"
1968-11-05
1968-11-17
1969-02-28
1969-09-24
1969-11-06
1969-11-11
1970-01-02 (Radio)
1970-01-02 (Bootleg)
1970-01-31
1970-03-18
Stereo from "English Rose"