Mauro Valli plays almost exclusively the baroque cello, but occasionally welcomes occasions to create interesting classical and romantic programs with the modern instrument. His modern cello is a copy of a Montagnana made in 1997 by Matias Herrera, a large instrument with a generous and warm sound. As a baroque cello he has an Andrea Castagneri built in Paris around 1740, an extremely fine instrument, very slim and elegant, with a sweet but penetrating sound. The second baroque cello is a small cello, a five-stringed instrument built by Lucia Valli and Matias Herrera in 1993. A very agile and comfortable instrument, with a very bright and bright sound that recalls the sound of the viola da gamba. With this tool it is possible (and philologically correct) to perform the baroque repertoire for violin, as well as of course the sixth Bach suite written for this type of instrument along with a dozen of Bach arias. There is then a whole series of works by Italian authors who, being written in a tenor key and in a register that would force the use of the capotasto positions, (historically anachronistic as adopted only later by Boccherini and his contemporaries) are clearly designed for a five-stringed cello.
Finally, Mauro Valli has an arpeggione that he uses for the execution of the Schubertian masterpiece (the sonata in a minor called “Arpeggione”), an instrument that has been self-built with the indispensable help of Matias Herrera and Lucia Valli. The instrument is a copy of the arpeggione present in the museum of historical instruments in Berlin. The next instrument, just finished building by his sister Lucia Valli and his brother-in-law Matias Herrera, is a baryton, the instrument for which Haydn composed innumerable works dedicated to Prince Esterhazy who was a virtuoso and passionate about this instrument, whose peculiarity consists in ‘have a series of strings that vibrate for sympathy, placed under the keyboard, but which can be pinched with the thumb of the left hand being the handle open. Haydn in his baryton trios in fact provides that the instrumentalist accompanies pinching the bass line.