They, along with Breen's three older siblings (Gertrude, Sally, and Michael), migrated from Kiev to Montreal, Quebec, Canada, in 1927.

His singing talent as a boy soprano was discovered at age three by his sister Sally, herself an aspiring musical student who was several years his senior.

Financed by Sally, they traveled to Chicago by bus in 1934,[8] where he began working with people such as Gloria Swanson and Milton Berle in local theater productions.

Film producer Sol Lesser, who had discovered Jackie Coogan, signed Breen to RKO Radio Pictures.

[10] Around this time, he became a regular performer on Eddie Cantor's weekly CBS radio show, "Texaco Town," in 1936,[11] where his talents as a boy soprano were appreciated by the listeners.

Prior to the release of his first motion picture, Let's Sing Again, he was compared to other child stars of the era such as Freddie Bartholomew and Shirley Temple.

[18] As a result, he retired from the film industry, despite being originally contracted for two additional movies,[19] and instead focused on his education at Beverly Hills High School.

He and fellow Hollywood actor Mickey Rooney were soon assigned to entertain the troops, despite him having retired from show business.

[30] Throughout the 1950s and 1960s, he worked as a singer in nightclubs and as a musical performer in stock theatre, later serving as a guest pianist for the NBC Symphony Orchestra on radio, and hosting a local TV show in New York.

Berry Gordy had hoped for Breen to become his first white contracted artist, but ultimately changed his mind because the singer did not suit the type of music Motown produced.

[31][32] In 1953, Breen appeared on ABC's reality show, The Comeback Story, to explain how his career nose-dived as he entered his teen years and how he fought to recover.

[33] Since the 1970s, he and his wife Audrey had been working in Florida as entrepreneurs, booking agents and producers arranging musical shows performed by various entertainers at smaller, affordable venues.

[11][20] In later years, it has focused on hiring aged stars of the past, including Debbie Reynolds, Mickey Rooney and Ann Blyth.