What sends shivers down your spine when you play it on your system?

Casta Diva - Maria Callas

I don't know what it means (nor want to know), it just sounds other worldly.

Any death metal song with Hillary Clinton singing lead vocals sends shivers down my spine.

Agree with anything Ava Cassidy. When she sings "I'm getting ready..." Water works every time.

ZZ Top - Bluejean Blues 

Chet Baker Sings. It's amazing how much music heroin has given us and how much music it's taken from us.

Morten Lauridsen’s Lux Aeterna and O Magnum Mysterium.

There's a lot but this is something most of you guys probably don't know:

turn it up - then go ahead and buy the hi res version from a site:
https://www.youtube.com/watch?v=oOT2-OTebx0