Masks lent an aura of mystery and mirth to a purposeful party Saturday night at Santa Rosa’s historic DeTurk Round Barn.

The occasion was the 4-A-Child Masquerade Ball, a benefit for the Child Parent Institute, formerly the California Parenting Institute. Almost always referred to as CPI, the Santa Rosa-based nonprofit provides classes and services aimed at ending child abuse by strengthening families.

Tarot readings kicked off Saturday’s frivolity. As guests enjoyed a taste of wine and perused the silent-auction tables, emcee Mike McGuire, the Sonoma County supervisor and state senator-elect, introduced singer Andrea Ingraham.

Guests made donations in exchange for casino chips, and played the tables.

Dinner was a buffet cornucopia featuring grilled chicken, pasta primavera, roasted baby potatoes, salad and local breads.

The rockabilly dance band Lost Dog Found played two sets. In between was a program with stories of the lives and families made better by their discovery of CPI.

McGuire delivered an impassioned pitch for cash gifts to sustain and expand the agency’s work.

The strike of 10 o’clock was the appointed moment to remove one’s mask.