On November 20th of last year, The Gorillaz performed an acoustic set on the BBC Radio 1 show along with singer Daley. The performance includes Doncamatic and a special cover of The xx - Crystalised. They also did an exclusive stripped back version of On Melancholy Hill which is featured in the above video.
Im not a huge Gorillaz fan, but these tracks are are nothing short of amazing and beautiful. I haven't found an official release of this show, but here is the unofficial version for everyone to hear:
03. On Melancholy Hill