A groundbreaking singing programme that has run in more than 500 schools is at risk because of Assembly government spending cuts, the charity behind the project has warned.
The CanSing pilot was launched in 2009 in response to evidence that teachers lacked confidence when teaching singing, leading to a reduction in pupil take-up and a decline in standards.
Funded by the government and run by community schools charity ContinYou Cymru, the pound;500,000 project aims to re-establish a tradition of singing in schools and help restore Wales's reputation as the "land of song".
The project has won plaudits from musicians including opera star Bryn Terfel, who said he was pleased at the government's renewed focus on music in schools.
But project manager Suzanne Barnes said that although CanSing was "overwhelmingly well received" by teachers, its future is uncertain.
The project is due to end in August and the website, which offers free resources, has guaranteed funding only until the end of the school year.
In his response to the recently published review of music in schools, education minister Leighton Andrews mentioned the project but failed to guarantee future funding.
Ms Barnes said: "To lose it all now would be devastating. Long have we been famous as the land of song. The tradition needs nurturing, investment and long-term commitment."
Ms Barnes said singing can have physical, psychological, social and educational benefits. "Singing is also a fantastic tool for teaching a whole range of subjects," she added.
"The CanSing approach capitalises on opportunities to develop, including reading, writing and critical thinking. Unfortunately, the arts often suffer in times of financial challenge. Perhaps we shouldn't ask if we can afford to invest in our young voices, but can we afford not to?"
Ms Barnes hopes an independent evaluation of the project, currently taking place, will provide an unequivocal case for additional funding to present to the minister.
CanSing has worked with schools across the country to promote singing, both in and out of lessons, and to aid pupil transition from primary to secondary school.
Each cluster of schools received two days of support from a team of singing specialists, and a lead teacher in each school was given two days of specialist training.
A spokesman for the Assembly government said: "The CanSing project is due to end in August 2011. By that time the government, in partnership with ContinYou, will have supported every local authority across Wales with training and resources to raise standards and promote the benefits of singing in schools.
"Any consideration of continued support and development will need to take into account evaluation evidence on the impact of the programme."