A USB OTG adapter provides a very convenient means to add storage to an Android phone.
Once plugged to the phone's micro-USB connector, one can connect a USB stick with music to the other end.
However, it seems that foobar2000 can't see the connected stick.

It is possible to use it, though, but in a very crude way: using a file explorer (e.g. ES File Explorer) it's possible to navigate to the device, open the required folders until one reaches the music files; after that, clicking on the file it's possible to open it with foobar2000.
- it's necessary to select and click each file in order to play it (no lists);
- obviously, files on the stick do not appear in the library.

There's really no support to USB OTG (or maybe my device is not compatible)?
Would it be possible to add support to USB OTG?