Formed more than 40 years ago, the English electronic group Depeche Mode likes to call itself "the biggest alternative band in the world." And yet, while lead singer Dave Gahan and lead songwriter Martin Gore began 2023 with a new album, "Memento Mori," and a packed tour schedule, they are doing so without their bandmate, Andy Fletcher, who died unexpectedly in May 2022. Gahan and Gore talked with correspondent Luke Burbank about their success, their addictions, and why they credit music with saving their lives.