Not Exactly the River Jordan

O sinner let’s go down,
let’s go down
Come on down,
O sinner let’s go down,
down in the river to pray

This is probably some family member(s) getting dunked in a North Texas cattle tank circa 1920-30ish...I'm guessing from the cars and horse drawn carriages. Since Granny Dee was a devout member of the Church of Christ (and went nuts when her oldest daughter wore pants *gasp* and started the local women's softball league in the 1950s), I'm thinking this was a C of C baptism, who like Baptists, practice baptism by immersion exclusively.