For the record, Under the Double Eagle was composed by Josef Franz Wagner. I found banjo tab for it here (click), which has the following information about the tune:

written in 1903 by Josef Franz Wagner (1856-1908), a military bandmaster and composer who was known as the "Austrian March King." The title is in reference to the double eagle in the coat of arms of the Austro-Hungarian empire. "Under the Double Eagle" was recorded three times by John Philip Sousa.

I woulda thought it was an American tune about an American eagle, but little do I know. Let's hear it for the Hapsburgs!!!!
There's a MIDI here (click) - and a nice band arragngement MIDI here (click). There's a really classy arrangement at Sibelius.com - but you have do download their free SCORCH ActiveX control (well worth your while).
-Joe-