Let's take the PYP production, for example. (And here is when I diverge into rumours, since it's just what I've seen in passing...) The students learn to sing a song for the production, while in class. Towards the end of the rehearsal period, the students are assessed in class for their singing abilities. Can they sing this song? How are their rhythms, pitches, pronunciation, etc. Then, they go out and do the production. Some of them might not sing in production because some of them might be in the soundbooth or helping backstage. The production, of course, is filmed for parents and put on Vimeo. In the next two music classes, the students watch the entire show with reflection sheets in front of them and they need to answer questions. Was the singing clear? Were people using the correct blocking, etc? The reflection sheets are tailored to the age of the students, so if it's an Early Years student doing the reflection, then the teacher reads out the question and the students colour happy, neutral, or sad boxes. Meanwhile, the reflection sheets for grade 5s are much more complex.
When I taught grade 5s, my assessments were often daily checklists. As the kids were in small groups working on their recorders, I had a checklist of things like:
- correct hand is on top
- air control gives a good tone
- rhythms and pitches are correct
- are they playing their own or a borrowed recorder
I used Karate Recorder, which is a great curriculum (kids find it very motivating), and so I'd also simply look and see who was where in the curriculum. When it came time for reports, I had notes on learner skills (e.g. self-management) and academic skills (playing the recorder).
I hope this helps.