Nancy Jacobs and Her Sisters, Baby Are Yeng.
Caveat auscultator: this song has the potential to infest the brain, so that years after hearing it, while you are waiting in line somewhere in an airport or bank, the refrain will come back to you unbidden. "Baby are yeng...down down Chicago...Chiiii-cah-go!!" (One testimony here.) But enjoy--it also swings harder than any other track waxed in '56.
Nancy Jacobs, along with Dolly Rathebe and Dorothy Masuka, was one of the preeminent female South African singers of the '50s. Her best-known track is likely "Meadowlands," a protest song about the razing of Sophiatown. "Baby Are Yeng" is on the now out-of-print Township Jazz 'N Jive.