Ultimate Tango School of Dance in Medford Square presents its annual Milonga with Santa, featuring the Boston Tango Orchestra accompanied by Argentine singer and actor Milton Loyaza. The BTO’s sets will be at 8:15 and 10 p.m. There also will be a Baked Goodies Contest with a chance to win tickets to Ultimate Tango’s New Year’s Eve Extravaganza on December 30-31. Tickets are $20 per person and available through the Ultimate Tango website.