Agostino Agazzari didn’t just compose music; he wrote the rulebook for how it should be played. Born in Siena in 1578, this Italian composer and theorist is best remembered for a single, game-changing book published in 1607. Del sonare sopra ’l basso con tutti li stromenti e dell’uso loro nel conserto wasn’t just another collection of scores. It was one of the very first instruction manuals dedicated to performing from the thoroughbass.
Before this, Renaissance music was a democracy of voices. Every line mattered equally. Agazzari’s treatise signaled a shift toward the Baroque era, where hierarchy emerged. The bass line became the foundation, and the upper parts became the ornamentation. He didn’t just observe this change. He codified it.
The Roman Years and Siena Return
Agazzari’s career was built on institutional prestige. Between 1602 and 1603, he served as chapelmaster at the German College in Rome. By 1606, he had secured the same role at the Roman Seminary. That same year, he joined the Accademia degli Intronati in his hometown of Siena. It was a significant honor. The academy was a hub for intellectual and artistic elites.
He returned to Siena in 1607, the same year his treatise was published. He spent the rest of his life there, working as an organist at Siena Cathedral and serving as chapelmaster until his death in 1640.
His musical output reflected the transition between eras. He wrote in the stile antico —the conservative, polyphonic style of the late Renaissance. He also embraced the stile moderno of the early Baroque. His catalog includes the pastoral opera Eumelio (1606), five books of madrigals, motets, masses, psalms, and other sacred works. But his theoretical work had a louder impact on music history than most of his compositions.
Defining Instrument Roles
The core of Agazzari’s argument in the 1607 treatise is a strict classification of instruments. He divided them into two distinct categories based on their function within an ensemble. This distinction was not arbitrary. It reflected the new Baroque aesthetic of contrast.
Foundation Instruments
These instruments provided the harmonic structure. They played the thoroughbass. Agazzari listed:
– Organ
– Lute
– Harpsichord
– Theorbo
– Harp
Ornament (Melody) Instruments
These instruments carried the melodic lines above the bass. They added texture and decoration. His list included:
– Lute (used melodically)
– Theorbo (used melodically)
– Harp (used melodically)
– Cittern
– Bass lira
– Violin
– Guitar
– Spinet
– Pandora
“Whereas in Renaissance music all voices of a composition had usually been of equal importance, in Baroque music a new and significant concept was emerging.”
The significance of this split cannot be overstated. It marked the end of the Renaissance ideal of equal-voiced poly
