The von Trapps of Harlem

When I enter the de la Mottes’ home—a three-floor, red brick townhouse in Harlem, around the corner from the Apollo Theater and down the block from a Verizon store—the somber thrum of a double bass echoes upstairs. 

I’m greeted by Amber, 43, who looks plucked straight out of an old-timey hearth catalog in a pleated emerald skirt and white blouse, her lon…