Anyway, my sisters and I already had a few pieces prepared because we had sung them at a garden party in the summer. What was requested were songs that may have been popular in the 1950's. Well, I knew that this lady had sung trio music with my mother years ago, so I took the chance that these arrangements we knew were perhaps some of the same arrangements that my mother had their trio sing in the 1970s. We inherited them from her anyway.
My mother and her sisters (Carolyn, Janie and Dorothy) sang trio music together as the Thompson Sisters from the 1940s on. Janie did most of the arrangements often using music from the famous girl trios of the day --- the Andrew's Sisters and the McGuire Sisters.
Everywhere my mother lived across the United States she provided entertainment for events. Sometimes she would gather some other ladies and teach them songs like this to sing.
Then, when my youngest sister grew up enough, our mother taught us to sing trio songs. We sang as the Lee Sisters (Betsy, Barbara, and Bonnie). Trio singing has been our heritage. Bonnie started her singing career with us probably at age 3. So, she started out singing lead (melody). Barbara always had a very low voice, so she sang Alto. That left me, the oldest, to sing whatever part was left, usually Second (which could go above or below the melody).