As a musician and a music producer, I paid for Dropbox primarily to be able to review audio on my phone in different listening environments (car, home stereo system, etc) with clients. But it appears that there is no possibility to have audio playing in the background, which literally every other media player app I use on Android does as a default. If there is no plan to either develop this for Android or enable Dropbox to utilize other apps (VLC) to play audio in background then I have wasted my money and will no longer be using Dropbox, nor recommending it for use to other producers.