Over the past two months, the experimental ensemble Wild Up and its artistic director, Christopher Rountree, have been presenting Darkness Sounding, a series of performances of mindful music during the darkest days of the year. In the Satsang 3 installment, vocalist-composer Odeya Nini alternately guides, soothes and challenges listeners in a kind of unpredictable music ritual involving a variety of chants, rounds and harmonies. Together we will gather for a song circle raising our collective voices in shared vibration, sound and song, the event website promises.