Hey dude I got Annalisa to check it out with her violin, and the first note doesn't exist. It's perfectly between Eb and E, which is gonna be pretty interesting trying to tune the guitar to it. Some notes work with an acoustic tuned to Eb, but just by chance.
Change your tin whistle or you might be able to change the tuning from 440 to 430 and try that.
EDIT: Or you could go all Nirvana and write something that's not really in tune but still sounds good, just find other instruments to accompany it. If you dig it, do it...fuck the rules...as long as it flows evenly.