Benedetto Marcello (1686–1739) was an Italian composer, writer, and magistrate of the late Baroque period. Born in Venice into a noble family, Marcello was expected to pursue a career in public service rather than music. Nevertheless, he received an excellent musical education and developed into one of the most respected composers of his time. Although he held various governmental positions in the Republic of Venice and later served as a governor in cities such as Pola and Brescia, Marcello remained deeply devoted to music throughout his life.

Marcello is particularly known for his collection Estro Poetico-Armonico (Poetic–Harmonic Inspiration), published between 1724 and 1727. This monumental work consists of musical settings of the first fifty Psalms, based on Italian poetic paraphrases by the writer Girolamo Ascanio Giustiniani. The collection was highly admired across Europe because of its expressive style and its blending of sacred tradition with contemporary musical language. Marcello combined elements of Gregorian chant, Baroque harmony, and operatic expressiveness, creating works that were both devotional and dramatically vivid.

One of the pieces from this collection is Psalm XVII a tres, written for three voices and basso continuo. The term a tres indicates that the work is composed for three vocal parts, often performed by combinations such as soprano, alto, and bass. In this psalm setting, Marcello demonstrates his ability to write clear yet expressive vocal lines. Each voice contributes to a transparent polyphonic texture, where the text remains understandable while the music retains harmonic richness.

The composition reflects the emotional depth of the psalm text, which expresses a plea for divine justice and protection. Marcello emphasises these themes through expressive melodic contours and carefully shaped phrasing.

Performed by Ensemble Salomone Rossi, conducted by Lydia Cevidalli, with an instrumental ensemble consisting of violin, cello, double bass, violone, theorbo and harpsichord, playing together with the Odhecaton vocal ensemble.