from code Geass
from the anime Planetes
from Code Geass
from Gun x Sword
from code geass
from code geass
from Code Geass R2 ep.20 (it was in other episodes, but i forgot exactly which ones)
from gunxsword
The famous song by Kuroishi Hitomi used in several Code Geass Eps: R1 ep.23 & 25 and R2 ep.19
Ending song of Code Geass R2 Ep. 25 by Hitomi Kuroishi