You'd definitely want to do that as an MP3 or Ogg. Wind isn't a GM instrument, so a MIDI version would work on very few systems.
It'd be small though, right? What about an SPC or tracker file? It should be less than 100 KB in any case. I mean, it'll be included by default with ZC, (Or next to it or something as a seperate download, perhaps.) so if it can be downloaded at the same time, it'd be nice. This alone could be the "enhanced music" for it at minimum, so it would work that way. Thanks. :)