I am sure you mean well, but you do your readers a disservice by suggesting "Manilow seeks to give his listeners the musical equivalent of a muscle relaxant". I have attended a number of Manilow shows over the years, and they are passionate, high energy, and full of big production numbers.
Even the Manilow name would not have justified a sell-out seven year run in Vegas if he just sang a few quiet love songs at the piano. Manilow has been called by Rolling Stone "the greatest showman of our generation" and the moniker is well-deserved. His shows are "events", with high production values and a number of upbeat songs (not just Copacabana!).
I sincerely hope you'll attend the show and review it--I bet it is nothing like what you're expecting. You may also want to check out his latest CD, "15 Minutes", an electric guitar-driven concept album about the perils of fame.