Instruct: Classify a given review into positive or negative sentiment.
Query: Quasthoff in mostly melancholy vein

Thomas Quasthoff and pianist Justus Zeyen, a sensitive duo partner, offer an interesting collection of songs by two composers of the late nineteenth century who were diametrically opposed in aesthetic sensibility. Quasthoff is on the upside of a major career and this CD supplies clear evidence why: his warm, darkly expressive baritone falls easily on the ear, but he is much more than a beautiful voice--his clear diction and attention to words brings the mostly slow and melancholy music to life. That being said, the preponderance of dark moods on this disc is a bit too much of a good thing--the overall impression is slightly monotonous, through no fault of the performers. It may be noted that the version of the Petrarch Sonnets Quasthoff performs on this album is not Liszt's own rendering for baritone, but the earlier, more vocally spectacular version originally conceived for a tenor voice, transposed downward.