Always one of my favorites, since I heard it as a young boy in Excalibur.

Carmina Burana O Fortuna, with lyrics that sound as if the Buddha wrote ’em:

O Fortune,
just like the moon
thou art variable,
always dost thou
wax and wane.
Detestable life,
first dost thou mistreat us,
and then, whimsically,
thou heedest our desires.
As the sun melts the ice,
so dost thou dissolve
both poverty and power.

Monstrous
and empty fate,
thou, turning wheel,
art mean,
voiding
good health at thy will.
Veiled
in obscurity,
thou dost attack
me also.
To thy cruel pleasure
I bare my back.

Thou dost withdraw
my health and virtue;
thou dost threaten
my emotion
and weakness
with torture.
At this hour,
therefore, let us
pluck the strings without
delay.
Let us mourn together,
for fate crushes the brave.

Chills at 2:22:

SolistInnen, Chor, Orchester der Volksoper Wien boten im April Fahrgästen und Passanten eine besondere Performance. Die KünstlerInnen lösten sich aus der Menschenmenge – eine “Passantin” begann, weitere “PassantInnen” – sowie als ÖBB-MitarbeiterInnen verkleidete KünstlerInnen – setzten nach und nach ein.:

http://www.volksoper.at

Bonus, Excalibur:

http://www.youtube.com/watch?v=emF-m9qnF5o

Bonus, full Carmina Burana, play it while you work? Better version? Link it in comments?