From 1965 (and the 1996 reissue of the Turn! Turn! Turn! album) please enjoy the David Crosby-penned backing track for The Byrds' uncompleted yet sci-fi themed "Stranger in a Strange Land."
The Byrds never finished this, for reasons that have never been satisfactorily explained to my knowledge, but what survives is, as they say, a hot one. Apparently there are lyrics somewhere, and some group actually covered it, with Crosby's blessing, at some point; if anybody has a clue, I'd love the details. Personally, I've always thought some smart alt-rock guy should write his own lyrics to the track and dub stuff on top of it.
In any case, as always a coveted PowerPop No-Prize will be awarded the first listener who gleans the clip's relevance to the theme of tomorrow's Weekend Listomania.