Taylor Swift has once again proved she is the best friend a girl could ever ask for. Like, ever.

The Blank Space singer couldn't help but pull out all the stops for her BFF Abigail's 25th birthday in Nashville over the weekend, surprising herwith a particularly special guest!

As well as the usual celeb suspects being in attendance (most of Kings of Leon, Lily Aldridge, Hayley Williams), Chris Carrabba, the lead singer and guitarist from Dashboard Confessional, made an appearance to sing THAT song.

[related]Being Abi's favourite band since High School, Chris singing Hands Down right next to you is probs the ultimate dream come true.

In thethree part video, Taylor is seen introducing Chris before they all join in fora sing-a-long to rival all others. EVER!

HANDS DOWN THIS IS THE BEST DAY- oh, wait, we weren't invited? Sob.