Joan Tower’s pieces often start slowly, with soft, long notes, as if they needed to establish something simple before they can assert themselves more strongly. These long notes are often written off the beat, though there’s no way you can hear that, because nobody is playing on the beat. There’s no way to tell that one note falls exactly on the unspoken pulse, while another note might hesitate, falling just a hair behind it.

But these little hesitations—and little surges, when a note comes just before the beat—have an emotional effect. They make the music unpredictable, and supple. The notes shape themselves into melodic lines, and these sound fresh and new, because they unfold so freely.

And this is only how the pieces start. Later on, they’ll often gather energy, growing forceful and decisive. These are two sides of Tower’s music. It can be quiet and emotional, and also strong.

Tower was born in 1938 just north of New York City. But she grew up in South America, where her father worked as a mining engineer, and there she developed a love for rhythm. She went to Bennington College in Vermont, and then to Columbia University, where she got a doctorate in composition in 1978.

Columbia, back then, was a center for atonal music in America, and like many other composers, Tower fell into the serial/atonal orbit. This helped her build subtle musical constructions, but wasn’t much good for her love of driving rhythm. She had to find her own voice, and when she did this, Messiaen was a big influence, especially his Quartet for the End of Time, a piece that unfolds with perfect freedom, not tied to any orthodoxy. Tower’s music soon became completely individual, full of sharp and lively dissonance, but also using gentler chords, along with pulsing rhythms and yearning bits of melody that could have come from tonal works.

In 1969, she founded what became a prize-winning chamber ensemble, the Da Capo Chamber Players, and here we have another key fact about her career. She’s a performing musician — a pianist — and she writes music for other musicians. Thus her music is closely married to whatever instruments (and instrumentalists) she writes it for. On this recording, the four piano works are wedded to the piano; the solo oboe part in Island Prelude would thrill any oboist; and Wild Purple, a solo viola piece, bitingly brings out the untamed sound of the viola’s lowest string.

So it was hardly surprising that her music—with its freedom, its lyricism, and its lively rhythms—had such a great success. Tower became one of the first composers to serve as composer in residence with an American orchestra (the very fine St Louis Symphony), and went on to get performances with countless orchestras, commissions from such notable chamber groups as the Emerson, Tokyo and Muir Quartets, the Chamber Music Society of Lincoln Center, the Kalichstein-Laredo-Robison Trio, and many other distinctions, including the international Grawemeyer Award, perhaps the most prestigious honour any composer can win. She’s a member of the Academy of Arts and Sciences, and the American Academy of Arts and Letters, and since 1972 has been Asher Edelman Professor of Music at Bard College. Recently she was chosen as the first composer to participate in “Made in America,” an unprecedented programme that commissions pieces for performance by orchestras in all 50 American states.

Though these biographical facts can’t capture how much fun Tower can be, and how outspoken she is. She says that when new music is neglected, even the great dead composers suffer, because people don’t listen to their music with the critical ears they’d bring to new work. When she gives pre-concert talks about her music, she often talks about parts of her pieces that she herself doesn’t like, to encourage her audience to form its own opinion.

About the works on this recording:

The string quartet In Memory began as a tribute to Margaret Shafer, a close friend who had passed away. But, as Tower says, “9/11 hit about a month later and the intensity of the piece got higher. It veers between pain and love and anger.” The pain and anger get quite wild, but still each section of the piece grows naturally out of whatever came before. At the end, the piece subsides into a single note, pulsing softly with a gentle breath of grief.

Big Sky, for piano trio—piano, violin, and cello— “has an image of a big landscape,” Tower says, “a Montana-like sky and maybe a lone wild stallion roaming freely within that. Sometimes he is staring at the peaceful gigantic blue sky, other times running wildly and freely over the green mountains.” The music can be rapt and intimate, with the piano wandering through yearning high notes in the violin. But then the horse begins to run, and the music rushes upward, finding its release in shining, rocky, rhythmic chords.

“I think of the viola sound as being purple,” Tower says, and that accounts for half the title of Wild Purple, her solo viola piece. And the other half? “I wanted to try and write a fairly virtuosic piece for viola,” Tower says, “and there is an ‘inside’ viola story here because the viola is never thought of as particularly ‘wild.’” The viola usually sounds veiled and reticent — but not here! Things begin very quietly, but soon there’s a jagged interruption. Next we start hearing two notes at once, and then the piece moves higher, conquering new space, exploding with ferocity.

Next come the four piano pieces, written separately but published as a group, all with titles taken from lines in a John Ashbery poem, No Longer Very Clear. The first piece, Holding a Daisy, is about Georgia O’Keefe’s flower paintings, Tower says, “which are so powerful and almost scary in their strength.” Simple chords grow into something big and strong; the ending, calm again, sounds more like a pause than a conclusion.

The next piece, Or Like a...an Engine never stops moving. As you listen, try to guess what’s going to happen next; it won’t be easy. Vast Antique Cubes softly and slowly explores what Tower calls “widespread piano spaces.”. It especially likes to wander upward, though it reaches firmer destinations than you might expect. The final piano piece, Throbbing Still, is, as Tower says, “another motoric piece that brings in some of my Stravinsky and Bach-like memories.” It’s full of surprises, and in many places seems to throb, with arousing rhythms, while the piano texture and the harmonies remain the same, thus creating an impression (as the title might suggest) that the music somehow moves forward, and at the same time stands still.

The recording ends with Island Prelude, for oboe and string quartet, though there’s also a version for oboe and string orchestra, and another for oboe and woodwinds. Here the oboe, Tower says, should sound “like a big solo bird.” She wrote the music for her husband Jeff Litfin, and tried, as she says, “for something with love and sensuousness. I thought of the setting as a tropical island somewhere in the Bahamas.” The oboe plays aching, longing melodies, but also flies with vivid, passionate arousal. At the finish, the music doesn’t seem to end; it simply stops.

Greg Sandow