Karen did not know the words to the song, so she read them from a paper napkin as she sang.
This is the first time, first take of her singing the song. Her brother was so blown away he refused the idea of a second take.
Songs were transposed to utilize Karen’s chest voice and her contralto. At the same time, her vocal microphone, a Neumann U87, has a proximity effect where the low-end register is emphasized with close distance, and this was used here.
The accuracy and precision, decades before AutoTune—and that vibrato, my goodness.
Karen did not drum on this recording. That was Hal Blaine.