They were be performing Taylor's current rising single 'Red', also joined by instrumentalists Sam Bush, Edgar Meyer and Eric Darken.
For an artist who has made her allegiances to the pop world very clear, this seems quite a strange decision to perform with such legendary and respected country/bluegrass performers. However, I suspect it will help re-promote her as a country artist, as she's barely making ground with country fans these days.
I guess Big Machine aren't done with her "roots" just yet.
The 47th annual CMA Awards will air live on November 6 at 8pm EST, on ABC from Nashville's Bridegstone Arena. The show will be hosted by Brad Paisley and Carrie Underwood.