AM-3P from DDR 2ndMIX has 4 versions in total, and TYPE4 was the one used int the main series games. This particular version is one of the other three, two of those three being "underground minimalist" versions according to Naoki, and this particular version can also be heard in the Records and Nonstop Order menus in DDR 2ndReMIX.
Since there's audio of that version on the internet, I wanted to download it and do something interesting in it, by playing that version of AM-3P in 2ndReMIX with the Challenge chart from DDR ULTRAMIX 4. And no, I did not hack the game to replace the audio. What I did was editing the audio over the video, not just editing the alternate audio over the original, but also readding the announcer and crowd sounds into the original video, using a 2ndMIX announcer folder I had lying in my hard drive. That's how I made the audio seamless.