Hi Jules, I have a subclass of AudioSampleBuffer that needs to change channels etc. Thus the members of AudioSampleBuffer needs to be protected rather than private (an alternative to this would be the possiblity to change what data the AudioSampleBuffer points to after it is constructed).
This is also applicable over JUCE generally, as JUCE is a framework library. It is rather likely, if not extremely likely, that somewhere, sometime a class needs to be subclassed. Private pretty much stops this cold.