Taking its cue from certain general features of the cultural history and from a strong focus on the theatre of events, this work first examines the theoretical background to the relationship between music and spirituality (from Augustine to the 'musical' mystics of the Middle Ages), then verifies its resonance in the post-Tridentine era - a period that distinguished itself for the ways in which it united singing with catechesis, art with prayer, and literature with mysticism. The attention then gradually concentrates on the exemplary histories of the composer, the poet and the collection (G.F. Anerio, Agostino Manni and the Selva armonica) that form the main, though not exclusive, object of close analysis. The Selva is in fact an excellent point of observation, for it is where many of the trends of turn-of-the-century Roman musical culture intersect. Blended together, thanks also to the possibilities opened up by monodic-concertato writing, are the rhythmic and colouristic dynamism of the minor genres (the canzonetta, and naturally also the lauda), the harmonic maturity and linear elegance of the Roman late madrigal and the natural contrapuntal mastery of the post-Palestrinian maestri di cappella. At the same time this variegated forest ('selva') is also founded on a perfect balance between the needs of docere, movere and delectare, while the expressive experimentation gladly allows itself to be ruled by rhetorica divina.