Experience the joy, virtuosity, and power of the Millennium Gospel Choir, which marks its 25th anniversary with a series of concerts that have become a beloved staple of the holiday season at the MFA. This year, there are four chances to see the group perform. Celebrate a quarter century of this renowned ensemble, comprised of preeminent musicians from Boston’s gospel community, with a classic tradition the Boston Globe has called “palpable” and “riveting.”