I am building a Music file organizer(in python2) in which I read the metadata of all files & then put those file in the required folder.
Now, I am already ready with the command line interface but this script shows feedback in a way that it shows "Which file is it working on right now?".
If the directory contains say 5000 mp3 files, there should be some kind of feedback.

So, I would like to know the most efficient way to find the total
  number of mp3s available in a directory (scanning recursively in all
  subsequent directories too). 

My idea is to keep track of the total files processed and show a progress bar according to that. Is there a better way (performance wise), please feel free to guide. 
I want my app to not have any kind of platform dependent code. If there is serious performance penalty sticking to this idea, please suggest for linux.
@shadyabhi: if you have many subdirectories maybe you can speedup the process by using os.listdir and multiprocessing.Process to recurse into each folder.
Effective way to find total number of files in a directory