The special kind of energy and inspiration in this music can perhaps be attributed to Tarquinio Merula‘s unstable character. His sacred vocal works are full of references to secular music: the psalms and motets use a “romanesca” bass and a whole mass in composed on a “ruggiero” bass; they include curious devices such as vocal “ostinati” and enigmatic canons. In the 17th century more and more instrumental music began to be performed during mass, so it was natural for composers to use musical elements which were common to secular compositions (with an ease uncommon to our present-day concept of sacred) to express the intimate emotional messages of sacred texts. Merula’s ingenious inventive vein is also apparent in his music for organ, permeating both the common musical genre of that time and “less modern” ones with vivacity and a search for new ideas.