Mivos Quartet. (Ralf Puder and Nana Franck/Handout)

The Mivos Quartet, formed in 2008 at the Manhattan School of Music, has put admirable focus and resources into expanding the string quartet repertoire, conducting workshops and competitions for new composers. Its all-British program Sunday at the Phillips Collection seemed a bit musty, then; the most recent piece, Thomas Adès’s “Arcadiana,” was written 20 years ago, and it was followed by an arrangement of a choral work by the Renaissance composer William Byrd and Benjamin Britten’s Quartet No. 3.

Adès is one of Britain’s leading composers, and his works have been performed by the Metropolitan Opera, the Emerson Quartet and the Berlin, New York and Los Angeles philharmonics. His music is influenced by Britten, but it is more severe and dissonant. In “Arcadiana,” the rhythmic challenges — individual notes changing on internal, asymmetrical fractions of each beat — tax the players’ concentration but add up to little more than a feeling of muddiness. Like Britten, Adès always has both a clear formal design and external artistic influences (in this case Greek mythology, a Poussin painting, Schubert and Mozart), but one wishes for more attractive musical ideas to go along with the aesthetics.

The Byrd “Mass in Four Voices” was a puzzlement. Arranged by Joshua Modney, one of the Mivos violinists, it was hard on the ears (a long work, played entirely non-vibrato and mostly with mutes), made harder by interposed transitions between sections that consisted of long, high, sustained harmonics. Rather than clear the palate, they set the teeth on edge.If this group is seeking something for a euphonious change-up between its harsher modern fare, I would counsel rethinking this one.

The Britten is a classic, of course, and welcome on any program, particularly as a closer for this one. The Mivos did an excellent job with the “Burlesque” movement, biting and scratching with energy and good coordination. The “Solo” movement was brought down by Modney’s parched tone, but otherwise this performance did the piece justice.

Battey is a freelance writer.