HANOVER, NH - Known for poise, balance and intelligence as well as "high-spirited, rhythmically propulsive energy" (Los Angeles Times), the Australian Chamber Orchestra (ACO) returns to the Hop to perform with the jaw-dropping Swedish-born Martin Fröst - whose "virtuosity and musicianship [are] unsurpassed by any clarinetist" (The New York Times) - on Sunday, April 19, at 7 pm in Spaulding Auditorium.

Last here in 2012 for a ravishing performance of Winter Morning Walks (which later won a Grammy), ACO in this concert spans three centuries with works by Haydn, Prokofiev and Jonny Greenwood, of the alt-rock band Radiohead, and, with Fröst, a Mozart concerto.

Founded 40 years ago as a conductorless orchestra and reinvigorated 15 years ago when it invited then-rookie conductor Richard Tognetti to occupy its podium, ACO has won an ecstatic and devoted Australian and international following, appealing to a broad range of people - including many who are new to chamber music - through the breadth of its repertoire and the zest and immediacy of its performance style, as well as extensive, inventive audience outreach.

Wrote The New York Times, "Intensity and virtuosity are hallmarks of this orchestra... There were plenty of fireworks and soulful moments in this passionate interpretation, enhanced by the musicians' vivid attention to color and dynamics." Chicago Classical Review praised ACO's "impassioned, full-metal performance... the tonal refinement and high-wire intensity demonstrated by Tognetti and his 16 colleagues also revealed the ACO as one of today's finest chamber orchestras." Wrote The San Francisco Chronicle, "[The ACO] plays with the sort of fleet rhythmic control and tonal purity that most chamber groups can only envy."

Fröst is typical of the A-list soloists with which ACO collaborates. Of the glamorous, globe-trotting player, reviewers have said: "Fröst exhibited a virtuosity and a musicianship unsurpassed by any clarinetist - perhaps any instrumentalist - in my memory" (The New York Times); "Martin Fröst performed faultlessly. His range of dynamic control was astounding" (Edinburgh Evening News); and "Masterful, self-assured, his variable playing and enunciating body language confirms this soloist as one of the best, most recognized respected soloists around the world... Surely some music fans were quietly thanking God that they had been allowed to experience this concert" (Anzeiger Harlingerland, Germany).

Fröst joins the ACO on Mozart's Clarinet Concerto in A Major, composed in 1791 and the last work Mozart completed before his untimely death. Mozart wrote the concerto for the great virtuoso clarinet player Arthur Stadler, a close friend, a fellow Mason and, on numerous occasions, a spirited gambling companion. "One would never have thought," a critic wrote of Stadler in 1785, "that a clarinet could imitate the human voice to such perfection."

Contrasting with the concert's 18^th- and early 20^th-century works is Water, by multifaceted British rock musician and Radiohead guitarist Greenwood, for strings, piano and South Asian instrument tambura. Inspired by a couplet from a Philip Larkin poem and by the composer's trip to India, Water includes "the spicy drone of real and synthesized Indian tamburas... providing a backdrop against which an upright piano and the 18 strings of the Australian Chamber Orchestra each do their own things with gently shifting melodic templates," wrote The Irish Times. "The recipe may recall Ravi Shankar and the colorful era when westerners from Messiaen to the Beatles flirted with Indian classical music. Yet the product has a lean level-headedness that could only belong to the present moment."

Speaking to Spin Magazine, Tognetti said of Greenwood: "I believe he's the first celebrated pop musician who has been able to straddle the world of classical music. In terms of the cross-fertilization of ideas, it's a great time to be a musician."

The 15 fleeting pieces that make up Prokofiev's Visions fugitives, Op. 22, based on a poem written by Russian poet Konstantin Bal'mont, were written for piano between 1915 and 1917 and then later transcribed for string orchestra. British musicologist David Fanning wrote of them: "Prokofiev supplies snapshots of his most characteristic moods - sometimes grotesque, sometimes incantatory and mystical, sometimes simply poetic, sometimes aggressively assertive, sometimes so delicately poised as to allow the performer and the listener to make up their own minds."

Written in 1785 when, under a new contract, Haydn was at last able to write for organizations other than that of his employer, Prince Nicolaus Esterházy, his Symphony No. 83, "The Hen" got its nickname "from an early listener's reaction to a lighthearted moment in the first movement of the work," wrote musicologist Ed Rutschman. "The oboe and the first violins seemed to suggest the motions and sounds of a hen, and the name 'La poule' stuck. Haydn's more profound accomplishment at this point, however, is to relate the new, lighthearted theme to the stormy opening theme of the movement by their sharing of a rhythmic pattern. The remaining three movements are an elegant slow movement, a minuet and a rambunctious Finale, all of which display Haydn's witty unpredictability."