The philosophy behind Music Together is based on research that all children are musical and the focus is on building music competence through adult role modelling. The music education for caregivers is interesting. If it weren't for my own musical education, I might find some of the information a bit more than I'd really need. But I'm geeky and I find it interesting.
What really matters is that S really enjoys the classes. He recognizes the songs and actually participates in the movements, playing with the instruments and "sings" along. He doesn't care if there are differences in time signatures, timbre, pitch, etc. He's just groovin' and having fun.