Streaming audio from Python to website: Which Tools/Technologies to use?

That's my project:

1) send GPS data from a clients smartphone to a Python program on my server 2) according to the GPS data an audio stream is manipulated with Python
3) send the audio stream to the smartphone

I'm a beginner, but I'm willing to learn anything necessary. I just need to know on what to focus (honestly, I'm lost in information). Therefore my question: Which tools and technologies should I focus on?

My assumptions so far:

referring 1): In order to get the GPS data into Python I need to use WSGI. Do you recommed a Web Framework like Django, Flask or Tornado?

referring 2): In order to manipulate and stream audio in real-time does the program really have to work asynchronously or in "non-blocking" fashion?

referring 3): In order to send an audio stream that's live manipulated I think that WebSockets is the right technology. I tried it server-side using the Python module "websockets" and client-side using JavaScript. That worked. But I wonder what's happening if multiple clients want to connect. I think I need some server program that deals with all those requests. I've read that my beloved Apache is no good choice as it is not designed to handle WebSockets. So maybe Tornado? But they want me to write everything asynchronously while I'm still learning Python...

I would appreciate any help.