Despite details both answers inform You, that there is no point in repetition of load/preload. ONCE You loaded OR preloaded resource blueprints are already prepared to be instanced, and You just need to keep reference from that 1st call, like this :
var music = preload("res/somepath")
and now it is written into your "music" variable. You are not supposed to call load or preload as void returning function
If You lose reference and instead call load or preload again - I am not sure if scene is being prepared again, but I believe it will have consequences on memory usage.