Hello my dear anon, I’ve found a few AUs for you :) But I also haven’t read them so no promises on Quality.

The Sound of Mutants by ourgirlfriday & Rohnoc (19k, NR) - Charles knew the danger that they faced in the war zones and deserted quadrants better than most, despite his never seeing the danger zones for himself; he’d been the one to tell her stories about the alliance and the rebels, after all, and later he’d been the one who had taught her about the war. Now he’s been brought to Genosha to teach the younger mutants on base at the behest of General Magneto.Or, X-Men very loosely influenced by The Sound of Music, in Spaaaaace.

Sound of Music AU by Gerec (T) - Erik calls off his engagement to the Baroness Frost and goes to tell Charles the news.

The Sound of your Voice by DrCHolmesLecter (WIP, On Hiatus, T) - It’s 1938 and Charles has constantly been getting into trouble with the nuns in the orphanage. Luckily, Moira found a job elsewhere leaving Charles to be assigned to work for Capt Erik Eiesenhardt-Lehnsherr.Capt Eisenhardt-Lehnsherr, a widowed naval captain needs a new governess to take care of his seven children but he ends up with a floppy brown haired, blue eyed man instead?

Hi Anon,

I was able to find only a couple of Sound of Music AUs :D

The Sound of Mutants by ourgirlfriday, Rohnoc 

Charles knew the danger that they faced in the war zones and deserted quadrants better than most, despite his never seeing the danger zones for himself; he’d been the one to tell her stories about the alliance and the rebels, after all, and later he’d been the one who had taught her about the war. Now he's been brought to Genosha to teach the younger mutants on base at the behest of General Magneto.

Or, X-Men very loosely influenced by The Sound of Music, in Spaaaaace.

And this one shot here:

Time and Distance by Gerec

Summary: As a child Charles unknowingly made a pact with an entity in the forest for protection against his abusive step father and brother. Ten years later the entity has returned.

Rating: R

Warnings: violence, major character death