pushed me out and slammed it. >> reporter: a determined poitier would spend months perfecting his acting skills and modifying his speaking voice. his hard work would pay off in a big way. >> i was right. i know i was right. >> reporter: in the 1950s he appeared in more than a dozen films beginning with "no way out" including an os-car winning performance in "the defiant ones." however it was his portrayal in "lilies of the field" that broke hollywood's color barrier earning him the coveted oscar for best actor. ♪ amen ♪ >> reporter: poitier never overcame his tone deafness lip synching the song "amen." poitier was considered a bankable star in 1967, starring in the landmark film "to sir with love." >> those kids are devil incarnate. i tried everything. >> reporter: playing characters that would force audiences to