I recommend CSM wholeheartedly
This school has great management which tries to cater all needs and be flexible. There are very good teachers as well – the key is to find one to develop a good relationship which works three-ways. This local school democratises the music teaching for everyone from a very early age unlike the well-established conservatories which only accept by audition. If your little ones like music and put dedicated effort to it, there is a path to the bigger schools as they progress, like two of my children now studying in RIAM.