Good news, Elizabeth Creith, there doesn't seem to be
a preexisting word to singularly describe your particular skill.

Soooo...

How about Whistlemaster or flutemasters?

Or maybe, whistlecrafter or windmaker
(naw, forget windmaker. people are so crude)

Let's see...we could suffix -artisans...whistleart?
No? Ok, how about whistlesudras, you know, after India's lowly artisan caste?

Me, personally, I like the Germanic sounding...guildersflute.

But best of all, I like... whistlemysteries.

Definition: my-ster-ies (archaic) craft making

What do ya think?