Barlow The Tax Avoider

Not that it was much of a secret but Gary Barlow and Mark Owen and the other one from Take That who nobody knew have been found cheating on their tax bill, or tax avoidance as it is called.
Much pressure now on gary Barlow, or 'the fat one from Take That' as Liam Gallagher called him, to hand back his OBE which the Queen handed to him in 2012 for services to Music and to Charity after HMRC have told him that investing millions in a tax avoidance scheme is a no-no and sent him a tax bill for the millions he tried his hardest to avoid paying. 
As a Conservative party supporter, David Cameron is not surprisingly as keen to speak up as fiercely as he did when Jimmy Carr was caught avoiding paying tax and the Conservative leader is fighting Barlow's corner in the should he hand back his honour debate.
I don't know much about tax but apparently there is something called 'tax avoidance' which is what Barlow and his Take That chums were doing but are not illegal and 'tax evasion' which is illegal.
How avoiding paying tax is different to evading paying tax i'm not sure, the outcome is the same in so much that you try to get out of paying the tax that you rightly owe and as the judge ruled on the case said that the scheme used by the band members and their manager were primarily designed to avoid tax, he should be subject to the same laws as anyone else who deliberately withheld tax from the tax collectors.
Maybe next time we get a bill from HMRC we write a letter saying 'Dear Revenue, i know i owe a lot of tax this year but i do a lot for charity so can you let me off please, thanks' and see how far we get.          
Once again it's one law for the wealthy actively looking to deprive the country of the money they owe and two fingers and penalties to everybody else.