Enter the sound world of Quatuor Mosaïques and check your expectations at the door. They perform on what we call period instruments: gut strings (rather than steel), classical bows (shorter than their modern counterparts), and less tension in the instruments. The resulting sound may be familiar when it comes from a larger ensemble playing, say, Bach's Brandenburg Concertos, but in a quartet, playing later repertoire, the experience is a bit through-the-looking-glass.
The lighter touch required for period instruments enforces a transparent texture throughout. If the sound of a quartet played on modern instruments comes rushing out to you, Quatuor Mosaïques draws you in. The dynamic range is more restricted than with modern instruments, and the balance between the voices is clearer. Because the players cannot dig into the strings, they must create articulation, phrasing, and accents through subleties of timing and color. As a result, even well-known pieces become revelatory experiences in their hands. For once, a string quartet does not sound like a concerto for first violin. Pianissimos are not tentative, but clear, and cantabile passages are phrased with consummate ease rather than fussy exaggeration.
The members of Quatuor Mosaïques met while playing in Nikolaus Harnoncourt's Concentus Musicus Wien, a pioneering ensemble of the period instrument movement. But the quartet's style is informed not just by academic research, but also by links to the vital performing traditions of the last century. Lead violinist Erich Höbarth was concertmaster of the Vienna Symphony and a student of the legendary Sándor Végh, who studied with Kodály and worked with Bartók and Casals. The quartet wisely eschews an unattainable ideal of authenticity; instead, they use period instruments as a means for approaching the music afresh. This approach was beautifully evident in the diverse palette of timbres and articulations they produced for a program of Haydn, Mendelssohn, and Schubert.
The concert began with Haydn's Quartet Op. 76 no. 4, nicknamed the "Sunrise" quartet for its opening motif. Haydn usually occupies a thankless role on the typical string quartet concert, the pleasant throwaway before we get to the heavyweights. But in the hands of the Mosaïques, who have specialized in Haydn ever since their first recordings in the 1980s, all the composer's humor and spontaneity were restored. Haydn's inventive harmonies were vividly realized, and fleet lines were tossed off effortlessly, without the gritty tension of some modern-instrument performances. During the rousing finale, the quartet played with gusto, bringing out the rustic elements of Haydn's style.