With his ninth studio album, “Gathering,” Josh Ritter keeps the torch for Americana music burning bright. Working again with the Royal City Band — along with a guest spot from Grateful Dead guitarist Bob Weir — the singer-songwriter’s latest balances folk and country influences with hints of gospel, while Ritter explores his place in the world. “I began with an exciting sense of dissatisfaction, and what emerged, as I began to find my voice, was a record full of storms,” he says.