Application crash when I try to play songs. Error " Open audio file stream failed."

[amitch001]

Two months before everything was working fine. But now Echonest has changed their Songs API elements from "title" and "url" TO "title" and "ID" elements of Songs.

Now I am confused how to pass a valid url of song using ID element of Songs api of echo nest. I tried the same method which i applied earlier for "url" element but now application crash and debugger says audio streamer object is not getting a valid url to read and stream file.

i am able to load songs from echo nest service on my application but when i choose a song application crash.

[amitch001]

can anyone please tell me how to convert a string identifier (like AFDGHFJKDLFKG) into NSURL......I attached the screenshot of my code where i am creating audistreamer object.