Tosca (Viennese producers Rupert Huber and Richard Dorfmeister) have been inducing quality buzzes in downtempo fans since their 1997 debut, Opera. On their third studio album, Tosca diversify their rich, bass-heavy sound to new heights of creativity. Deploying a variety of singers, the duo repeatedly hit the sweet spot between dubadelic splendor and midtempo house-y sensuality. Further, two tracks recall David Byrne/Brian Eno’s menacing funk classic “Regiment,” while two more luxuriate in tropical bossa climes without sounding trite. A second CD of 12 melancholic, minimalist piano works with subliminal drones and dubby FX conjures images of Harold Budd tickling ivories while Monolake stirs soups of gray noise.