There is something eerie about that music at the beginning with the slight static cutting in and out. Kinda sounds like something you'd hear on a radio in Half Life or some post-apocalyptic and Horror style stuff.
It is broadcasted to North America over half of the world. Medium waves reflecting against ionosphere lose some of their fidelity. Hence why they cut in-and-out.
You don't want a strong signal, otherwise you would be located in North Korea. Be happy with what you have, and fine-tune the signal to the best of your radio's abilities.