What exactly is meant by musica reservata, a term that is mentioned about ten times in 16th century literature, is still not entirely clear. The closest interpretation is in the more "social" sense, namely that it is music "reserved" for certain people, i.e. reserved for connoisseurs, and which therefore makes high demands on understanding in terms of its facture. The sources that could contribute to the interpretation of the term suggest four areas: - musical text interpretation, - rhythm, - chromaticism and - performance practice. The best-known description comes from the Dutch humanist Samuel Quickelberg, who wrote of Lasso's penitential psalms: "Lasso, who - where necessary - added plaintive and mournful tones to the thoughts and words, emphasised the strength of the individual affects and made the subject matter almost come alive before our eyes, expressed the content of these psalms so perfectly that one can hardly say whether the sweetness of the affects adorned the plaintive tones, or the plaintive tones adorned the sweetness of the affects even more richly. This kind of music is called musica reservata [...]" Very often Orlando di Lasso is mentioned in this context as the composer of the time who dealt most profoundly with the principles and innovations of musica reservata. 

Lasso was probably born in Mons (Henngau) in 1532. He received his first lessons at the age of 12, in the service of Ferrante de Gonzaga. During his employment he travelled to France and Italy. From 1556 Lasso lived in Munich, where he was employed by Duke Albrecht V. In his first years he was not very happy. Although he received large commissions for compositions, the duke forbade him to print them and considered them the property of the Bavarian court. This also affected the two cycles Prophetiae Sibyllarum and the Septem Psalmi poenitentiales. Even though it was feared that he might leave Munich because of his good contacts with other courts, he remained employed there until his death on 14 June 1594. 

The Prophetiae Sibyllarum is a cycle consisting of twelve six-line Latin poems and a three-line prologue. The theme of each of the twelve poems is the prophecy of a sibyl. The interpretation of the text, to which particular importance was attached, was not exactly easy because of the complexity of the verses. Lasso, however, saw it as a challenge and mastered it with the help of chromaticism. This was particularly suitable for the interpretation of affects and underlines the mystical character of the prophecies. It is questionable whether the entire cycle was actually performed at the Bavarian court as part of the office. 

The second half of the 16th century in France is dominated by Claude Le Jeune. An active member of the famous "Académie de Poésie et de Musique", a foundation of Antoine de Baïf, this composer is not limited to renewing music by returning to the principles of antiquity, but also - like some of his contemporaries, e.g. Guillaume Costeley or Anthoine de Bertrand, he engages in theoretical research carried out in Italy by Nicola Vicentino, and applies extravagant chromaticism in some of his works, for example in "Qu'est devenu ce bel œil ».