bluetooth headsets and software synths?

[C.M. Brannon]

Hi list,
I recently bought a bluetooth headset and a USB-to-bluetooth dongle.
I can access the headset using aplay and arecord. For instance, the
command "aplay -D plughw:1,0 test.wav" plays a file on the device.
I want software synths to use the bluetooth headset, rather than the
built-in sound card.  Is that possible?  How is it done?

Thanks,
-- Chris