Riddle Eight

Riddle Eight: For Mein Fraulein

Difficulty: 9
Interest: 3

Apparently, the title refers to some encrypted message called For Mein Fraulein. This message is very similar, with the music at the beginning, except that the sequence of digits probably do not mean anything.

It might also refer to Number Stations

According to the page source, there is some text hidden 'in plain site'. This isn't in the rest of the source or the title, so you'll have to take it from the image (no need for any image manipulation).

This will lead you to an audio clip. The weird sound you might not understand means zero. Find the right sequence.

Next Level

*Spoilers*

The image has some text written at the bottom-right. For those who have difficulty reading it :
audio/212-796-0735.wav

Find the sequence that differs from the others, and write it this way: xxxxx.html