Hi! I'm kind of a noobie with Arduino so please bear with me 
I have an MKR1000 (has WiFi capabilities) and I've set up a Flask server which serves a web page consisting of only an audio file. I want the MKR to connect to the webpage (would be 127.0.0.1:5000/audiofile.wav or something) and download the file and save it to the SD Card. I've heard of the WiFi101 library, can it be used to download the audio file? Thank you!
Interesting question, if someone has done sth similar please share what did you do.
I think you can't download an audio directly, maybe you can download a file, regardless its extension, byte by byte or as a datastream. Then into your code reassemble the data, and save it into the extension you want, easier to say than done.
btw, a monophonic audio you can reproduce with your arduino and a buzzer, but more sophisticated ones you need an external reproducer.