Robbie Robertson in Boulder Storied songwriter and guitarist Robbie Robertson will open this year’s Boulder International Film Festival with an in-person appearance at the screening of “Once Were Brothers: Robbie Robertson and The Band,” festival officials said Wednesday. Tickets for the March 6 event at the Boulder Theater, which includes a red carpet gala and after-screening Q&A with Robertson, also went on sale Wednesday for $95 via biff1.com.