Mateja Tomac Calligaris was interested in pedagogy from an early age, although she initially studied medicine. Attending one of the Willems® Music Teachers seminars led her to music pedagogy. In 1994, she obtained the Willems® Pedagogical Diploma in Italy and a year later, in Ljubljana, she started working with her first students. She graduated from the Faculty of Education in Trieste in 2002.
In the same year she founded the Edgar Willems® Music Centre (GCEW), which has become an important part of the Slovenian educational system recognised by the Ministry of Education. Since its establishment, Mateja has been leading the GCEW and collaborating with many Slovenian and foreign pedagogues and artists.
She is also an active member of the Slovenian Society of Willems® Music Pedagogy and Vice President of the International Willems® Federation.
In July 2018, in Lyon, she was the first Slovenian to receive the Willems® Professional Didactic Diploma. She conducts seminars in the field of music pedagogy in Slovenia and participates in training activities elsewhere in Europe (Italy, France, Spain, Switzerland).