Glen Tomasetti was well known in the Melbourne folk music scene of the 1950s and 1960s as both a singer-songwriter and a guitarist. She established the Emerald Hill folk concert sessions during the 1960s and for some time performed weekly on Channel 7, singing protest songs. Tomasetti cut eleven albums in the 1960s; her Songs from a Seat in the Carriage was published in 1970. She also collaborated with Tim Burstall (q.v.) and composer George Dreyfus on the soundtracks of a series of short films about colonial Australia. Tomasetti also directed fringe concerts for the Adelaide Festival of the Arts, staged her own one-woman tribute to Bertolt Brecht and helped found the National Folk Festival.
Tomasetti was strongly opposed to the Vietnam War and was a member of the Save Our Sons Movement in Victoria. She became a heroine of the feminist movement in 1969 when she adapted the words of an old shearing gang ballad, 'All Among the Wool Boys', to support the case for equal pay that was heard in the High Court that year. The song became 'Don't Be Too Polite, Girls'.
In addition to her songwriting, Tomasetti wrote history, novels and poetry. Her debut novel, Thoroughly Decent People : A Folktale (the first book managed by McPhee Gribble publishers) dealt with domestic life in suburban Melbourne. Her second novel, Man of Letters : A Romance, was again concerned with women's lives, but this time in the context of academia. Tomasetti's poetry was published in a range of journals, including Overland and Meanjin, and was also anthologised.