It's easy learning the song to slow down time unless you ignore everything, I think you can find the scarecrow in 2 places (unless it's somewhere else and I'm not aware) in Clock Town. Once you get the song of time and its inverted version everything is easier.
Now I agree that the game it's pretty damn hard. First temple is not a big deal but the other ones... I remember the first time I played Stone Tower temple I didn't even get to the half of it with time slowed down.. lol







