Somewhere between a band and a concept, the Canadian group Broken Social Scene has persisted both grandly and modestly since 1999. It’s grand in sound and personnel, with 15 participants on its new album, “Hug of Thunder”; it’s modest in constructing its music collectively, even though it’s packed with individualistic songwriters.

The collaborators on “Hug of Thunder,” the band’s first album since 2010, have grown up together and, by now, have also built their own careers, yet they still work on Broken Social Scene. Keeping its options open, the group gathers its loosely knit crew of clamorous, flexible musicians behind songs that are ready for a big soundstage: an exultant surge of instruments, voices and wide-open reverberation that Broken Social Scene delights in applying.

Sound has always subsumed lyrics in Broken Social Scene. Its 2001 debut album, “Feel Good Lost,” was largely instrumental, and its songs since then have flaunted long introductions and interludes where hooks and intricate countermelodies pile up. Something particularly Canadian — hearty, thoughtful, knotty, communal — unites bands like Broken Social Scene, Arcade Fire and the New Pornographers. On the surface, in these bands, the music’s crescendos usually signal euphoria. But “Hug of Thunder” holds a growing disquiet.