The Royal Conservatory of Music (Canada) in Toronto offers a comprehensive teaching method encompassing strict guidelines for ten grade levels. The ARCT and LRCT diplomas for Teachers or Performers is the culmination of all the grades which is also recognized worldwide. Comprehensive theory and history co-requisites are required to obtain a certificate. Many Canadian provinces recognize completion of higher levels of the curriculum, awarding students high school credits upon successful completion. The Royal Conservatory operates The Glenn Gould School, a centre for professional training in classical music performance, a Community School, an educational initiative for public school teachers, a Young Artists Performance Academy, and it offers RCM Examinations. Some of Canada's most famous musicians studied at the Conservatory. Glenn Gould studied theory, organ and piano, graduating at age 12 in 1946 with an ARCT diploma, with highest honours. Teresa Stratas, Lois Marshall and Jon Vickers were also Conservatory students.