Chesus, Rodski, Stroud and Tony Blitz.

It's not C.S.N.Y. but their DJ/Producer equivalent. C.R.S.T stands for Chesus, Rodski, Stroud and Tony Blitz, four DJs/Producers from South Wales making music and remixes by sampling wide variety of genres...from house to hip hop, to drum and bass. Check out a couple awesome remixes.
Shelter - The XX (C.R.S.T Rmx) by C.R.S.T

After Dark (C.R.S.T Rmx) - Count and Sinden feat. Mystery Jets by C.R.S.T