'Random Dances and (A)Tonalities'

The last set is over, and the club is almost empty. The bassist has already gone home, the drummer is walking out the door. That leaves the saxophonist and the pianist, but they decide they're not done yet. They have more ideas to exchange, more confidences to share. They begin to play again, only this time just for themselves.

Do most saxophone and piano duets start out this way? Surely not, and yet the best of them could fool you, with their intimate, nocturnal ambience, their exploration of 'songs of love and regret', as the saxophonist Marion Brown and the pianist Mal Waldron called their 1986 album. On Random Dances and (A)Tonalities, the new album by the pianist Aruán Ortiz and the reedman Don Byron, the music is unapologetically cerebral, like the title. One of Ortiz's compositions, the crepuscular 'Numbers', is a work of 12-tone serialism; another, 'Arabesques of a Geometrical Rose (Spring)', is based on what he calls a 'triangular relationship within a series of three notes'. Ortiz likes to 'generate content' from mathematical formulas, but the results are unexpectedly sensuous. 'Math can be poetry,' Ortiz says, and so it is with Random Dances and (A)Tonalities.

Ortiz was born in Santiago de Cuba in 1973, and studied at the conservatory in Tarragona, Spain. After moving to New York, he became a protégé of the late pianist and composer Muhal Richard Abrams, the founding father of the Association for the Advancement of Creative Musicians. Like many musicians trained by the AACM, Ortiz often speaks of musical influences as 'information'. He has woven those influences into the distinctive tapestry of a personal style: the rumba, yambú and bolero; the work of composers such as Olivier Messiaen, György Ligeti and Conlon Nancarrow, and of AACM leaders like Richard Abrams and Anthony Braxton; and, not least, the tradition of jazz piano, from stride to Monk, from Cecil Taylor to Geri Allen. He has a graceful touch, a suppleness of time that prevents his structuralist preoccupations from rigidifying (he also loves the extreme lower and upper registers of the piano, and sometimes plays inside the strings).

In Byron, who turns 60 in November, Ortiz has found an ideal duet partner, an expressive improvisor who is also a formidable musical thinker and composer. I last saw him perform in Harlem a few years ago at a private memorial for the artist Terry Adkins. Accompanied by the pianist Jason Moran, he played John Coltrane's 1963 ballad 'After the Rain' on tenor saxophone, his round, creamy tone stirring memories of Lester Young, the subject of his 2004 homage Ivey-Divey. I'd missed hearing Byron, who, for me, will always be the sound of New York in the early 1990s, the era of the Knitting Factory, when he seemed to play everything: fastidious hard-bop and raucous avant-funk, klezmer and cartoon music, West Indian popular songs and Schumann lieder. He was also outspoken about racism and injustice, and made one of jazz's most powerful protest albums, the 1992 Tuskegee Experiments, named after a 40-year study of black men with syphilis who were left untreated so that doctors could track the long-term consequences.

A few years ago Ortiz was playing in a band led by the drummer Ralph Peterson Jr. 'I told Ralph I loved the chord changes he was using, and he said: “I got them from Don Byron.”' Ortiz was dazzled by Byron’s ability to 'play all those crazy avant-garde lines with that traditional sound', something he'd been trying to do on the piano. Byron also shared Ortiz's curiosity in compositional forms and complex harmonic systems. Ortiz invited him to perform with him at a concert at Harlem Stage in 2013. After the concert, they continued their conversation over email. In late 2017 they went on a two-week European tour as a duet. At the end of the tour, over two days in December in a studio in Zurich, they recorded Random Dances and (A)Tonalities.

Most of the ten tracks on the album were completed in a single take, but they're performed with a lithographer's attention to detail. By 'random', Ortiz explained to me, he does not mean 'unsystematic' but rather that 'there's nothing you could locate in an actual groove, but it's there underneath, and you can feel it.' This is chamber jazz by two master improvisers who understand that the essence of a duet is not only playing, but listening – and that playing and listening are inseparable, crucial to the feeling of 'closeness', as the bassist Charlie Haden called his 1976 duet album.

Four of the tracks are by other composers: Duke Ellington’s 1927 'Black and Tan Fantasy', played at the languorous pace of a New Orleans funeral march; Geri Allen's tribute to Eric Dolphy, 'Dolphy's Dance', a 32-bar blues in which Ortiz and Byron move from vertiginous, unison lines to slinky counterpoint and back; Bach's Violin Partita No. 1 in B minor, played without accompaniment, or adornment, by Byron on clarinet; and an eerie, agitated piece from Book 1 of Musica Callada, a sequence of piano miniatures by the Catalan composer Federico Mompou. Ortiz admired the way Mompou had combined the spare melodies of Erik Satie, whose work he'd studied in Paris, with the songs of Catalonia, where he wrote Musica Callada between 1959 and 1967. Through this synthesis, he says, Mompou achieved the 'complexity of simplicity'. This is what we hear in Ortiz and Byron's austere and restrained performance, which draws powerful and unsettling emotion from a handful of notes. The conclusion leaves us hanging, with Byron blowing high, ruminative notes over Ortiz's left-hand chords. 'Mompou's music doesn't land the way we expect it to, and the resolution is like a door to what's happening next,' Ortiz says. 'Mompou's pieces have a lot of these doors, and they give a lot of space to creativity.'

That feeling of unsettledness and irresolution also permeates the pieces that Ortiz and Byron have written for Random Dances and (A)Tonalities. Byron's 'Joe Btfsplk' – named after the character in Al Capp's comic strip Li'l Abner – at first suggests a Charlie Parker tune, but the banter between tenor and piano hints at something more ominous, as they snake warily around each other. Their dialogue eventually acquires a dark and furious density: an allusion, perhaps, to the rain cloud over Joe Btfsplk's head that symbolises his bad fortune. On Ortiz's composition 'Tete's Blues', a rhythmic pattern on the piano creates the illusion of a single rhythmic frame, until you realise that Ortiz and Byron are sliding in and out of different rhythmic frames. The effect of these displacements is at once seductive and disorienting, and the disorientation intensifies the seduction. 'I don't hear tonal centres, I hear textures,' Ortiz says. 'I'm trying to create a wavy way of hearing tonal centres that come and go.' But you don't need to understand all the waves on Random Dances and (A)Tonalities to ride them with pleasure.