“She’s Not There.”
Oh, wait. You meant about zombies. :smack:
The Flamingos “I Only Have yes for You” (chi-bomp chi-bomp)
Plenty of them, but for now I’ll just mention “A Pillow of Winds” by Pink Floyd, “Evening Star” by Fripp & Eno, and “Flying” by the Beatles.
Since this thread was opened, we now have a better place for music-related threads. Off to Cafe Society.
“Feels So Good” by Chuck Mangione. Although it’s bittersweet for me now since it was the song that was playing on the CD in my car when I left my mom after she died. 
Cochrane! Were you referring to songs BY zombies?! I doubt any of THOSE would be serene… :eek:
*Sitting on the Dock of the Bay *- Otis Redding
Remember (Christmas) - Harry Nilsson
“Silent Lucidity” is one of my favorite Queensrÿche songs; it doesn’t deserve the hate.
Well, okay… maybe it does deserve the hate. But either way, it’s a beautiful song. 
She’s Not There is not very mellow, but Time of the Season might qualify.
Anything by J.J. Cale, the king of “laid back”.
When I really need to chill, it’s either Crosby Stills & Nash, or James Taylor.
It’s not just about music that is mellow in and of itself; it also has to be music that I am so familiar with that it doesn’t demand any attention from me; it is like an old, comfortable pair of butter-soft jeans. They just do their job and let me focus on my need to chiiiiiiiiiiill the fuck out.
Human Racing by Nik Kershaw
No One Is To Blame by Howard Jones
Yes, shameless 80s music fan.
Crosby, Stills and Nash? Does “Marrakesh Express” qualify?
Sarah Mclachlan - Angel
Though now I can’t listen to it without picturing starving animals thanks to that commercial.
JEM and Bjork performing Leaving on a Jet Plane is also awesome.
“Reminiscing” by the Little River Band