Toi was born on June 18, 1916, in Kõo, Viljandi County. From 1932-1936 and 1941-1944, he studied choir direction, organ, composition and conducting at Tallinn Conservatory.

In 1944, Toi fled from Estonia to Germany, where he led choirs and organized concerts and smaller song festivals in displaced persons (DP) camps. In 1949, he emigrated to Canada, where he first settled in Montreal before moving on to Toronto in 1951. For decades, Toi was a leading figure in the diaspora Estonian choral movement, leading a number of diaspora Estonian choirs, but also served on the faculty of the Royal Conservatory of Music (RCM) in Toronto.

He had studied at the University of Chicago, the RCM, the Institute of Advanced Studies in Montreux, Switzerland, and the University of Toronto.

One year before Estonia regained independence in 1991, Toi joined Gustav Ernesaks and Richard Ritsing to serve as honorary directors of the XXI Estonian Song Festival in Tallinn.

In 1994, Toi symbolically led the song festival's return to freedom following decades of Soviet occupation, conducting the opening song of the XXII Song Festival in 1994.

Toi most recently visited Estonia in 2014, where he celebrated his 98th birthday and participated in the XXVI Song Festival as a guest of honor. His 100th birthday was celebrated with a number of special events in his longtime hometown of Toronto.

Toi, an honorary citizen of the city of Viljandi, was the oldest living member of the Estonian Composers' Union (EHL) as well as the last living member of the fraternity korp! Vironia to join before the occupation. In Canada, he was likewise the last living founding director of the Estonian Foundation of Canada (ESK). He was bestowed Estonia's Order of the National Coat of Arms, Fourth Class as well as a number of decorations by the Estonian Evangelical Lutheran Church (EELK).