Radius premieres Ruehr’s ‘Quetzal Garden’

CAMBRIDGE — You'll occasionally hear from musicians that certain seemingly complex works aren't as hard as they sound to a listener. The opposite is true of Elena Ruehr's music. As flutist Sarah Brady put it on Saturday at a Radius Ensemble concert, Ruehr's new piece "isn't as easy as it sounds."

Brady was introducing "Quetzal Garden" for flute and string quintet, the first of four new works Radius is premiering this season (one on each concert). Its muse is a rare and exotic bird, whose songs are simulated in Brady's playing. Ruehr is well known for hiding complex structures beneath simple structures, as she once put it, and though "Quetzal Garden" has an inviting exterior, there are a wealth of rhythmic displacements and subtly intricate counterpoints. It must take a lot of skill to create such airy textures, as well as a seamless construction that sounds perfectly proportioned, not to mention the profusion of effortless melodies. Ruehr's art is to never let craft get in the way of an unabashedly beautiful piece.

At the other end of Radius's program was the wind quintet "Aires tropicales" by the jazz composer and bandleader Paquito D'Rivera, a synthesis that lies some way between Cuban dances and a Western wind quintet. It's brilliantly colored, and some of its most interesting moments are those that leave the dance rhythms behind and plunge into some tangled harmonies, such as the movement dedicated to Dizzy Gillespie. Radius's performance was careful, even a bit staid, though enlivened by the clarinet playing of Eran Egozy.

Between the two was Ligeti's 1982 Horn Trio, an homage to Brahms and one of the most successful negotiations between tradition and modernity in music's last half-century. Ligeti borrows the older composer's structures and patterns and fits to them music that straddles the line between tonality and atonality. It is also music of immense emotional power: The three instrumentalists speak in distinct dialects that seem at cross purposes, so that the music bespeaks isolation and loneliness. The trio was the dawn of a new compositional epoch for Ligeti, but the thundering bass notes at the end connote instead some dark twilight.

The performance, by violinist Gabriela Diaz, pianist Sarah Bob, and horn player Anne Howarth, was not note-perfect but it was fervent and illuminating. So was Howarth's illuminating discussion of Ligeti's use of the horn's natural partials from the stage.

Radius Ensemble

At Pickman Hall, Longy School of Music of Bard College, Cambridge, Saturday