Soundtrack research

The sort of theme we are going for is horror, this means we have to build the tension with a slow to past pace and with the soundtrack we use. We were thinking of using a heartbeat most of the way through buliding the tension. The heartbeat would be used whilst we are have it at a slow pace when we fade out shots eventuallly bulding up then changing the music to something that has a slow bass to it still with a sort of heartbeat to it but having a faster pace music above it.