I've been compiling some <80 minute mixtapes comprised of songs generally over 7 minutes in length, and preferably over 10 minutes. The premise is to collate very long tracks which are good to work to and in which you can get happily lost while scribing/fiddling with Excel/whatever...

As an example, my acid style rock mix goes:

1983...(A Merman...) - Jimi Hendrix 13.39
Star Blanket River Child - Brightblack Morning Light 10.29
Cop Shoot Cop - Spiritualized 17.14
Marquee Moon - Television 10.40
Turn of the Century - Royal Trux 7.07 (it fit in quite well, even if it's a bit short)
Three Days - Jane's Addiction 10.49
Kashmir - Led Zeppelin 8.35

I think it actually works quite well. Sorry that there's no Spotify playlist but I can mixcloud this if you're interested.

What extravagantly long tracks do you rate and how would you compile them? And has anybody every done a mixtape of ultrashort tracks (say under 2 minutes each)?