After finishing DO NOT DISTURB, I went to the special features.
The first one was entitled "The Rise of Doris Day" detailing her years training as a dancer, her car accident, and her studying to be a singer and then singing with various big bands.
Stupidly, Fox hasn't gotten any stills from that period of her life, so they illustrate all the chattering experts with stills and video clips from her three Fox films made late in her career. Dumb!