An update that might be of interest to folks researching male ancestors from Norway. I have two that came from the Trondheim area. One, Johannes Absalonson, Flaa (aka John Flow when he came to US) graduated as a youth from the Norwegian National Military School in Trondheim. He served five years in the Norwegian "standing" army as a musician (bugler) and then came to America where he enlisted in the US regular army again as a bugler.
I will pursue the records of the military school in Trondheim if I can find someone that knows about the enrollees during the early 1880s. He was born in 1867 and I don't know when the "youth" were old enough to attend. Maybe it was in place of a "high school" education. I believe this great uncle was very talented and ambitious and wanted to emigrate to the US as soon as he was old enough (19)