Upload background music; lower volume during voiceover replay

1. I have my own "on brand" licensed music that I want to use.

2. Additionally, it would be incredibly awesome to have TWO volume settings, an additional one with a lower volume during voiceover replay, with a very quick fade-out/fade-in from "normal" volue to "voiceover" volume. That would truly ROCK THE HOUSE of SUPADEMO!

Thanks guys, keep up the great work, I'm impressed with what you've implemented already.