The grammar school rhythm band. According to the description in the annual:

"The Rhythm Band made great progress this year and were a welcome group of entertainers. They performed in P. T. A., a chapel program, and the all school music achievement program...The sponsors of the rhythm band were Miss Daisye Setliff and Mrs. Gladys McCord. Miss Setliff directed the band, and Mrs. McCord was pianist."

Picture taken from 1941 "Wolverine."