Ds is usually pretty good at practising although he has to suppress his perfectionist tendencies. Today he lost it with a chromatic scale on c (which in theory he should be able to do with no problem as it featured in his exam last summer). The next half hour featured various snorts and squeaks and "GO AWAY" with a couple of bars from his pieces thrown in, here and there. When I went into his room he was hiding under his duvet sulking.
Is this normal? Ds is 9 and he's chucked his music on the floor in frustration a couple of times before (but tends to express frustration through overblowing the highest notes).