Wednesday was a big day for Massachusetts-bred band Godsmack. The four guys spent the afternoon at their headquarters in New Hampshire being filmed by a European documentary film crew, and then traveled down to the Newbury Comics at Faneuil Hall, where Mayor Marty Walsh proclaimed Aug. 6 Godsmack Day in Boston. The event celebrated the band’s sixth full-length album, “1000hp,” which was released this week. Before heading out to meet the mayor, Godsmack frontman Sully Erna told us that the documentary shooting up in New Hampshire won’t take the place of the feature the band’s been filming about itself for years. “That’ll hopefully have a theatrical release,” he said, of the band’s own doc. Erna also told us that he’d never met Walsh, but that he had some things to discuss with him. “I’m actually trying to get a studio at Boston Children’s Hospital,” he explained. “There’s been such success with music therapy.”Names can be reached at email@example.com. Follow Mark Shanahan on Twitter @MarkAShanahan. Follow Meredith Goldstein on Twitter @MeredithGoldste.