Well a company called TroubleAcres has an app that can play music off a USB stick on your XBOX one. It is free and it works, but it is very simple. It only plays MP3, WMA and FLAC files on a FAT32 or NTFS USb drive within a folder called “Xbox Music Library” and it has a limitation of only 200 files and plays them in alphabetical order. It does read files in folders, but only to add to the alphabetical list.
It works and I can finally play my own music. Just have to keep it to 200, and put music on I want at the time.
I am on a Mac and use ALAC files, which are not supported, but luckily the $5 M3Unify app from the awesome Doug’s Scripts will convert to MP3 and put files in folders by artist and album. Of course for now those folders are useless, but hopefully it will work at some point. And ALAC support would be great too, since the One does support AAC in it’s Media Player app (which also supports a DLNA, and folders, but for some inexplicable reason doesn’t support Background Music making it next to useless).