A huge number of children who wish to learn a musical instrument are being denied the chance - and opportunities are diminishing because music is an "easy target" for budget-slashing local authorities, the EIS told MSPs.
The union hit out at councils for making "profits" of almost pound;3 million from charges to pupils for learning an instrument, after analysing figures obtained under Freedom of Information.
"They obviously see instrumental tuition as an easy target," said Mark Traynor, of the EIS's instrumental music teachers' network, in evidence to the parliament's education and culture committee. He estimated that there were enough children wanting to learn an instrument to employ as many as three times the number of instructors currently working around Scotland.
But the cost was reducing the numbers signing up, with 24 councils charging between pound;95 and pound;340 a year for tuition.
The fact that six councils charge pupils for entry to SQA music exams was seen as clear evidence that music continued to be treated as a lesser subject.
"If you were to charge for Higher English there would be an outcry," Mr Traynor said.
Some committee members expressed unhappiness that local authorities body Cosla had not come to give its side of the story.
A Cosla spokesman was "very disappointed" at any implication that it had been reluctant to take part, insisting that "it is simply a question of competing priorities - we are more than happy to assist the parliament at every opportunity on any issue".
Local authorities were "required by law to present a balanced budget every year and need to look at ways of doing this, and in doing so need to make difficult spending decisions", he added.
Councils which charge for tuition have defended their approach, saying that many pupils still receive free tuition and that income raised is put into music budgets.
The Sistema Scotland project, much-lauded for creating orchestras for hundreds of children from Stirling's Raploch estate, may soon expand to other local authorities.
Director of music Francis Cummings told the committee the pound;1,500 cost per pupil was value for money and benefited the community.
He said the project - based on a famous Venezuelan programme and in its fourth year of an initial five-year plan - had yet to take any public money.
Since it began its mission in 2008, Sistema Scotland has raised pound;3.5 million and its five-year commitment ends next summer.
Thereafter, Stirling Council will provide much of the funding, with Sistema Scotland covering 25 per cent of running costs.