I don't know if this is still relevant, but each tile (landscape cell) has its own file located at MapObjects\_(AdvMapTile)\Grass, Water, etc. In each of these folders, there is a line called AdventureMusic, where you can add any track/sound that exists in the game, or add your own by following the pattern of the existing ones.
Всякое/карты:
Добавление недостающей музыки гномам