Joan Dillon, a Masters graduate of RSAMD (now the Royal Conservatoire of Scotland), also claimed music at Mass was "more rooted in pop music than in sacred traditions" and was often "so bad it distracted people from the true purpose of worship".
She said 25 pupils from state schools currently learning Latin through the study of sacred music were the future lifeblood of the Catholic Church in Scotland.
Speaking prior to the launch of Scotland's first Academy of Sacred Music (AOSM) in Glasgow tonight, Ms Dillon, its founder, told The Herald: "There has been some pretty lousy music sung in Catholic churches and that is where things have gone wrong, why congregations are shrinking.
"It need not be so. As a parent myself it seems to me young people are being brought up immersed in the negative messages of modern music via MTV, a lot of which is demeaning.
"They need the transformative power of sacred music to balance that, but instead they are getting banal, happy-clappy stuff at Mass. Sacred music can lift young people up and help them embrace more noble ideas, yet it is not sung in many Catholic churches in Scotland."
Ms Dillon said the poor standard of church music stemmed from Vatican II, the Second Vatican Council convened in 1962 by Pope John XXIII which led to Mass being said in English rather than Latin. Her support for sacred music echoes that of leading Scots composer James MacMillan, who Ms Dillon has invited to be patron of the new academy.
Mr MacMillan was commissioned to write new sacred music for masses in Glasgow and Birmingham during Pope Benedict XVI's visit to Britian in 2010 and caused controversy within the Catholic church when he claimed, in a letter to The Herald, the trend for "touchy-feely-smiley-dancey folk" worship had "repulsed" young people and "put them off going to church in their droves".
In his address tonight at St Andrew's Cathedral, Glasgow, Mr MacMillan will repeat Pope Benedict's message that "the world needs beauty in order not to sink into despair" and that music is the most spiritual of the arts.
Asked by The Herald if he hoped the AOSM would improve the standard of sung music at Mass, Mr MacMillan said: "I have no doubt the initiative will have a practical impact. The AOSM is a wonderful development in liturgical music in Glasgow."
The AOSM, which is open to all religions and none, is based at Renfield St Stephen's Centre in Bath Street and runs choral classes for young people from the age of five to 18. It already has 25 students from state schools, including Glasgow's Holyrood Secondary and Uddingston Grammar.
Holyrood pupil Rosie Lavery, 14, said she would like her own church in King's Park to start a choir so she and her friends could influence what was sung. She added: "At the moment the music is sung by the congregation and it's pretty dull."