In this virtual era, it goes without saying that much of the communal aspect of a film festival has evaporated. Strangers don’t compare notes waiting inline or with their neighbor before a film begins. Reactions are confined to social media or you’re favorite message thread. And for Sundance, a festival that can launch a film into the stratosphere after one glorious world premiere, the loss of in-person screenings is even more painful. That being said, if there is any film that would elicit a buzzworthy standing ovation in both Park City’s gigantic Eccles Theater and in viewer’s living rooms it’s Sian Heder’s “CODA,” which was part of a slate of films to open the 2021 edition of the fest on Thursday.