Songs that are good, until a choir just kind of shows up and turns the knob to 11

I've been feeling pretty down lately, and would appreciate help in finding/being reminded of songs where choirs just kind of show up and absolutely level everything around them. The best examples I can think of are Foreigner's I want to Know What Love Is [rock] or Heart's cover of Led Zeppelin's Stairway to Heaven [rock] at the 2012 Kennedy Center Honors.

I'd appreciate any reminders of or suggestions for other songs that are good, until the choir shows up, and then they're GREAT that I can scream alone in my basement to feel better. The harder the rock, the more uplifting, the better.

Thank you advance!

ETA: Thank you all for your suggestions, they're coming in faster than I can look at them and I can't reply to them all to appreciate individually. I promise I'm going through the whole thread and every suggestion eventually; it's been a long Friday (a long week, actually) and work has sucked the life out of me so I'll be flopping into bed soon. Rock songs with "surprise choir out of nowhere" is going to be my jam for a while.

ETA #2: Here's a link that has as many of the suggestions as I could get.