My BA is in German Lit. I drilled our guys in German and IDed about half a dozen songs the Ninth would have sung. I also prepared the cultural research for a group to portray the 24th IL at Perryville a couple years ago.
Fair warning - there seems to be a sentiment amongst people who study history and within the living history hobby, both authentic and mainstream, that you can portray a "German" by learning a couple phrases, drinking some beer, eating some wurst. However, German cultures were (and still often are) very different, not just from American, but from each other as well. This sort of impression takes a huge commitment of time and effort to do correctly, and while that may be fine with you, it may be a difficult proposition to get others to buy into that effort.
At Perryville, the effort to provide German context was largely wasted because the aggregate didn't feel it was important enough to get the cultural part right.
Imagine. The
Hecker Regiment marching off to battle to the tune of "The Girl I Left Behind Me."
Good luck.