In the old days there were records. They had an A side and a (less important) B side. If you say something quietly, so not heard by most, it is an aside.
Yes I know that, but the clue contradicts does'nt it? It says ' the more important ' which is the A-side - but it then says it's NOT heard by most. Surely the A-side IS heard by most people and the B-side IS NOT heard by most?
Or is it me getting it wrong?
The beginning of the sentence is the more important part i.e. Aside. The second part of the sentence is a separate part with the same meaning - something that is quietly said and not heard by most is an aside. I thought like you when I first read this clue, but if you treat them separately it makes sense.