This one takes some time to properly set up, so feel free to skip to the last paragraph if you like:

DD7 has been taking guitar lessons for about 7-8 months now. DW and I were inspired by that to learn ourselves, so I bought us our own instrument, but DW hasn't touched it since the first day I brought it home, because arthritis in her hands has prevented her from forming proper chords. I suggested she try the keyboard instead, but the idea hadn't really caught fire with her.

I've already had significant exposure to music (choral), so I've moved ahead pretty quickly with the guitar, and I'm always helping DD practice, showing her some things she hadn't seen in class yet, etc. Meanwhile, DW has sat on the sidelines, watching us both progress, and I guess this slowly fanned that ember within her. This month she determined she was going to learn keyboard, and picked up a beginner's book. After maybe a week she gave up in frustration, and decided she just didn't have an ability to learn it. But I had looked at her book the day she brought it home, and I already knew the problem... she was basically expected to be fluent in reading music on day one. It bears mentioning here that DW had zero exposure to music, except as a listener, and a little bit of church singing. I told her she needed to use our guitar books, because they break down the staff into smaller, more digestible chunks. There are three notes on the first string you learn, with some exercises to practice, then three on the next, two on the third, and so on. They take a similar approach with rhythms, different keys, chords, etc.

So, Sunday morning, I grabbed a guitar book and the keyboard, and brought them to DW. I gave DW a quick description of time signature, a measure, and how many counts are a whole, half, and quarter note. Then I flipped the book open to the first exercise, with three notes. DD7 came to see what we were up to, and she hunted down a Sharpie to write the note names on the keys (they'd been written before, but DD and her friends played it so often they'd been rubbed off, and DD didn't need them anymore anyway). I left to buy donuts.

When I got back from the donut shop, DD7 was observing as DW played "Ode to Joy," which is a more advanced exercise from the second lesson, involving six notes, which DW was reading for herself. DD's magnetic board was lying on the bed, full of things she had drawn out to help explain various points. DW was really excited that she was playing actual music, and she was gushing with admiration, not only for how well DD demonstrated her own deep knowledge of the concepts, but also for DD's demeanor and ability as a teacher.