Nevrkla spoke out at his organisation's AGM at Kings Place in London on Wednesday on the issue as he compared how little in tax internet giants Apple, Amazon, Google, eBay and Facebook paid to the low earnings of most UK musicians.
He noted 90% of musicians in the UK, comprising tens of thousands of people, earned £16,000 or less from music. But he said the situation was worse than that as he recalled Musicians' Union general secretary John Smith last year proposed a motion at the TUC Conference about musicians and singers getting "blackmailed" into performing for no remuneration and then having to waive their future recording rights.
"This is true of many sporting events, cultural occasion, various fund raising activities and other events," he said. "I am delighted that the TUC Conference unanimously endorsed John's motion on the basis that performers must not be coerced into giving their rights away and work for nothing, especially as everyone else in the chain gets paid.
Now he said at the Olympics the same process had started all over again.
"Firstly came the obvious realisation that without music the Games will lack lustre, then the brilliant idea that it would be rather nice not to have to pay the musicians," he told the AGM.
"Letters are now being received by performers stating that there is no budget for music and therefore they should simply work for free. I do hope that, like me, you all find these practices shameful and deeply offensive, particularly in the knowledge that so many people, individuals and companies, have made enormous amounts of money out of the whole Olympic Games process."