God of Thunder/ModdingHelp
Each level is divided up into a number of screens. Only one screen is visible at a time in the game, and when the player walks off the edge of a screen, the game scrolls to the next one.
Each screen has two independent attributes - the default background tile and the song played as background music. In Camoto, these attributes are assigned to two independent layers. By deactivating (double-click) and hiding (right-click) all layers except the attribute layer of interest, one tile will be seen at the top-left of each screen.
In the default background layer, the tile here will be drawn behind all background tiles that have transparency in them, such as the edge of water, trees, etc. There can be only one tile per screen set.
In the song layer, there is also one tile per screen. The tile is a number between 0 and 9. This controls the song that will play when the screen is visible, according to the list on the God of Thunder Level Format#Songs page. (The number placed in the level is the "song ID" in that table.)