In the grand setting of the 2025 Amadeus, Amadeus Festival in Hamburg, Jordi Savall delivered a performance of Mozart’s “Great Mass in C Minor,” (K.427) that stood as a testament to the power of unfinished works. Collaborating with his longtime assistant and keyboardist Luca Guglielmi, Savall brought one of Mozart’s most intricate and incomplete masterpieces to life, blending historical scholarship with artistic inspiration.

Mozart’s “Mass in C Minor” is among his most ambitious yet unfinished sacred works, likely abandoned due to shifting priorities. The surviving sections reveal a masterful fusion of Baroque counterpoint and Classical lyricism, reflecting his deep admiration for Bach and Handel. Guglielmi’s reconstruction was grounded in meticulous study of Mozart’s surviving sketches and a deep understanding of his compositional style. Rather than introducing speculative elements, he focused on thematic and structural coherence, borrowing selectively from Mozart’s other works to fill the gaps. For instance, in the “Credo,” Guglielmi utilized contrafactum techniques to adapt melodies from “Davide Penitente” (K. 469) and the “D Major Mass” (K. 337), crafting a seamless auditory narrative. This thoughtful approach ensured the new material felt entirely organic, serving the integrity of the original composition.

The performance of Le Concert des Nations, while not entirely flawless in tonal refinement, was extraordinary in its emotional depth and vitality. At nearly 83, Savall took on more of a supportive role, allowing the musicians significant freedom to explore and express themselves. The joy and spontaneity radiating from the players were obvious, with smiles and moments of improvisatory flair punctuating the 70-minute uninterrupted performance. One of the highlights was the continuo-like interplay between the two cellists and Guglielmi on the organ, which brought a lively Baroque-inspired energy to the performance. This rhythmic pulse energized the ensemble, driving the music forward with cohesion and spirit. The woodwinds shone throughout the evening, their nuanced and expressive playing adding a soft glow to the soprano lines, creating a richly colored and beautifully balanced musical texture.

The choir, La Capella Nacional de Catalunya, delivered a masterclass in precision and power. In movements like the Sanctus and Gloria, their polyphonic lines soared through the Elbphilharmonie, filling the space with a sense of divine majesty. The “Cum Sancto Spiritu,” reimagined as a double fugue in the Baroque tradition, was a breathtaking display of technical and emotional mastery, as the choir’s voices wove seamlessly through complex contrapuntal passages with clarity and cohesion.

The soloists, led by soprano Giulia Bolcato and mezzo-soprano Lara Morger, brought depth and vibrancy to the performance. Bolcato’s “Christe eleison” was a highlight. Her clear, bell-like tone navigating the aria’s leaps and ornamentations with ease and emotional resonance. In the “Et incarnatus est,” her delicate phrasing paired beautifully with the woodwinds, creating an intimate moment of serenity. Morger’s “Laudamus te” sparkled with operatic energy, her vibrant phrasing and buoyant rhythms adding a joyful vitality to the movement.

As the architect of this completion, Guglielmi’s handling of the “Agnus Dei” was particularly brilliant, drawing thematic material from the opening “Kyrie” to establish a sense of cyclical unity. This thoughtful integration gave the Mass a cohesive narrative flow, making the work feel remarkably whole despite its incomplete origins. The final “Dona nobis pacem,” based on Mozart’s sketches for a double fugue, retained the contrapuntal rigor of the original while adding a stirring emotional depth. As the last notes faded, the audience erupted into thunderous applause, sustaining a standing ovation for over 10 minutes.

Savall’s interpretation of Mozart’s “Mass in C Minor” at the Amadeus, Amadeus Festival was a celebration of the unfinished. Guglielmi’s reconstruction was both intelligent and concise, striking a balance between scholarly rigor and musical intuition. His approach, firmly rooted in historical evidence, ensured credibility while offering a deeply satisfying listening experience. Through this seamless blend of fidelity and creativity, the music transcended its fragmentary origins to feel both complete and authentic. The result left the audience in awe, reaffirming the artistic vitality and timeless relevance of Mozart’s unfinished masterpiece.