Developing means not yet developed. Fine on a prep report. Not good on a year 7 report.
Developing well, however, is goodish. We're not yet entirely there, but I'm pleased with the direction in which things are moving. Hopeful that we'll arrive in good time for... Next year's report? Adulthood?
For me, basic is a variant of limited or developing.
Some means not much.
Roy can perform C major and minor scales, maintaining some level of accuracy. His duet, "Lightly Row", was performed to a basic standard. His sight reading skills are developing. Roy has demonstrated a limited understanding of music theory.
So what does Roy get overall?