I was finally able to see this in a VERY nice three-film boxed DVD set of Dick Barton Hammer films from the late 40s. The first two (D.B. Special Agent, and D. B. At Bay) were both pretty bleak. So, I went into the final film with no great expectations. I was REALLY shocked by how good it was. The film is greatly strengthened by some incredible location filming, especially the extended scenes atop the Blackpool tower. My personal favorite moment was the bandleader directing a real packed dance hall full of revelers. It gave the "Dick must save the world!" storyline a bit of added significance to see a bit of documentary Humphrey Jennings-like texture thrown in. The story itself, about a new "sonic" weapon that can kill whole towns with pure sound, was clever too...Four stars! Oh, yes, and the villain has a harpsichord; this is always a nice touch!