The MOST IMPORTANT key is to take the track and never clip any time off of it, if it was 3:35 seconds when you downloaded it, that’s what it ashould be when you mail it back with your new tracks on there. As far as software damn near anything will work, we are only dealing with mp3 s and wav files, no native formats. You can use pro-tools (what i use) or the easiest and must have program “audacity”, which is free, as long as no one trims the time down you can just drop it in and line it up. simple as it gets.
Now you have your track recorded and want to send it back—before you mail it to me it, put all the pre-existing music to one side, the left channel, and put your track to the other side, in the right channel, and voila—-we’re done and you’re in, provided that you have a shred of talent. For stereo tracks, just line it up with the existing tracks I made and DON’T TRIM ANY TIME OFF OF IT. I will drop it in and everything will be fine, I will sort out your levels in the mix. Send me two mixes, one with you blended in where you see fit, and one with your stand-alone tracks. AS LONG AS YOU DON’T TRIM ANY TIME OFF OF IT!
email your version to firstname.lastname@example.org