The mysteries of the human voice are endless paths, lost in a thousand and one trails of what Gerard Mortier called "sensualization of the soul." I was thinking this on Monday, while Bruno de Sá sang several arias from Baroque opera on the stage of the Palau de la Música, alongside Ensemble 1700, conducted by Dorothee Oberlinger. Both the ensemble and the conductor are quite versatile, both in instrumental pieces and vocal accompaniment, including Oberlinger's virtuosity on the recorder.