In Naruto Shippuden ep. 456 at around 14:48-15:35, there's a music which plays after Juzo sacrificed himself to save Itachi. The music starts at 5:09 in this YouTube video.
It's 100% Sai's Theme Song. The bit you hear in the Juzo death scene starts at 0:27 https://www.youtube.com/watch?v=enD0LhHJ8Gw
I think it's Sai's theme song or Danzo's or Konoha's root.