Did you know... the "Plug-in" mode was first launched with the release of Band-in-a-Box® 2010 for Windows!

With the 2010 "Plug-in" mode, Band-in-a-Box opened as a small always-on-top window, and acted as a plug-in for your favorite DAW/sequencer, so that you could Drag-and-drop MIDI and audio (WAV) tracks from Band-in-a-Box to your favorite sequencer. You could work in your favorite sequencer, type a progression in Band-in-a-Box, and then simply drag the track from Band-in-a-Box to your sequencer’s track at the desired track and bar location.

To learn more about the new features that were launched with Band-in-a-Box® 2010 for Windows, check out Band-in-a-Box® 2010 New Features Video:


The "Plug-in" mode feature is highlighted at 10:50!

The "Plug-in" mode development didn't stop there - With Band-in-a-Box® 2019 we introduced the "Band-in-a-Box® VST DAW Plugin" which now works DIRECTLY INSIDE YOUR DAW (Cakewalk, Reaper, Pro Tools, PreSonus, etc.). Learn more about this feature here.

If you could have a Plug-in Mode the same as RapidComposer or Fl Studio where the VSTi is just an small dll interface to the main app sending sync play/stop/loop/continue and receiving audio and midi from the main app.
This maybe an alternative if you can't get ReWire to work or the ReWireVST audio sorted, it would also give those who are well used to the main version all it's features.
Even if you can just get the sync to work you can use ReaStream to send audio/midi.