There's a set of tuning forks; Isabella has fine relative pitch but not enough of an approximation of perfect pitch to start on the right note out of nowhere. She finds the right one, strikes it, nods a beat, and starts.
Isabella pulls an old standard from her childhood music lessons - gestures to correct flats or sharps or overlong rests. He hasn't learned the library of signs, but she's only drawing on a handful and he seems conscious enough of what he's doing that he should be able to pick them up.
And, after its runtime, they are done. "There's a bunch of those signs. You want to know the rest? They're really handy. Also, you can use them as rude gestures if you want to insult someone who's singing, although I don't recommend doing that to anyone sensitive or humorless. Or anyone who'd take you seriously. Serah sharped Moriah so much one time that poor Moriah wound up transposed, a full step down."
"This one means you're rushing the phrase - this one is for taking a breath at the wrong point -" She goes through the rest of the musical errors and the accompanying warning signs for instructors or friends to use, repeating as necessary.
There aren't that many; a book on them would be very slender. She finishes up within a few minutes and then rests her head on his shoulder.
It gets to be rather late. Eventually they migrate from the music room to Isabella's quarters and change for the night and go to bed, her left wing draped warmly over him.
She doesn't have to go - she still has several days of the assignment-free week - but no one else is jumping on it. She gets a number of miles and an exact compass heading and then she hunts up Micaiah to see if he wants to come along. He doesn't know the prayers, but she could hold him and he could listen.
She sings. The air around them changes. She climbs higher, and clouds form below them. She sings, and the clouds open up and they rain.
She descends through the rain and lands in a patch of ground rocky enough to not yet be turning into mud. She accepts thanks and a quick lunch from the farmers, gives them a few days' worth of weather forecast, and then takes her leave, flies above the clouds again with Micaiah in her arms, and heads home.
He really is very cute.
If he doesn't wake before she lands she'll tuck him into bed.
Isabella goes back to her quarters, picks up one of her history books and a notebook in which to write musings, and reads, flopped on her stomach with one wing over Micaiah.