Hi erratica !
Welcome to the forum !....

The first thing you need in order to get a JS file into Audacity, is the All Access Pass so you can download an Mp3 of your song....then just open Audacity, select "Import File" (or something close to that), then go to your folder where your song is, highlight it, then select "open"...If you haven't got the All Access Pass yet, I personally think it's well worth the price....

...Hope this helps !
Dave