Real name: Penny and Patty Pollack

The Twin Tones (3) were twin sisters Penny and Patty Pollack who sang regularly on Los Angeles TV station KTLA's show "Western Varieties".
The name-spelling varied -- they also show up in internet searches as Penni and Patti Pollock.
They had three recordings on the Monte Carlo Records (3) label.
Surprisingly, one additional Twin Tones release on Monte Carlo Records (3) is actually the male duo The Twins Jim And John.