“Convivium” is Mario Diaz de Leon’s third album under his ONEIROGEN alias, and follows the “Plenitude” EP, released in 2015. It was developed over a period of two and a half years, primarily through live performance in the metal and noise underground of NYC. Like its predecessor, the album’s core instrumentation is an array of hypnotic synthesizer riffs, pummeling percussion, distorted vocals, and surging noise. With “Convivum”, Diaz de Leon has crafted a powerful and singular work of heavy electronic music.
“Like the rest of Sheen, ‘Bare Arms, Black Dresses’ was edited and layered from hours of free improvisation, recorded and mixed by Jamie Saft. Over 10 minutes, its delayed guitar loops and midnight clarinet moans move from syrupy metallic drone to sputtering, gnashing noise, replete with guitar skronk that sounds like the garbled remains of a busted Autopsy live bootleg.”
– Lars Gotrich, National Public Radio
“Toby Driver and Mario Diaz de Leon bring experience as veterans of extreme rock, noise and classical music, and on Sheen both men make liberal music of electronic layering and distortion. Cymerman is right there with them. On ‘Singing Psalms,’ for example, his clarinet’s voice is first magnified, then pixilated, and then utterly blasted like a solar flare over strata of digital filth and laconic guitar figures.”
– Bill Meyer, Downbeat Magazine
“It seems like only yesterday that NY-based composer Mario Diaz de Leon issued The Soul is the Arena, a collection of three bold contemporary classical works. But as those acquainted with Diaz de Leon’s work well know, he also issues material of a dramatically different kind under the Oneirogen (o-NI-ro-jen) name. Plenitude, an EP-length, five-track prelude to an upcoming full-length, perpetuates the uncompromising sound design first explored on 2012’s Hypnos and then a year later on Kiasma. In the two years since its release, Diaz de Leon has further developed the project’s sound via live appearances in NYC’s underground metal and experimental scenes. The music’s overall intensity doesn’t declare itself immediately, as “Oxygen” inaugurates the EP with three minutes of restrained keyboard chords and slow-building ambient atmosphere. “Collapsing,” on the other hand, wastes little time at all in laying out its doom-laden soundworld when seething synth riffs and hammering salvos of percussion set the nightmarish scene and Diaz de Leon’s vocals—reminiscent of early Nine Inch nails, the words are more screamed than sung—plunge it into a caustic doom-metal zone. And with the singing so heavily distorted, one turns to the package’s inner sleeve to review lyrics rendered indecipherable by their delivery. Though it might seem hard to imagine, “Vessel” is heavier still, with the roar of the singing matched by the brutalizing instrumental design. The title track, thankfully, offers a welcome respite from such intensity in augmenting softly whispered vocals with a glacial synth backdrop, after which “Emergence,” in a nice framing gesture, echoes the instrumental design of the opener in unleashing a vibrant array of declamatory synth statements and portentous bass throbs.”
-Textura
“The Soul Is the Arena is Diaz de Leon’s latest chamber-music album since Enter Houses Of, and it’s both shorter and more all-encompassing. In three different pieces that collectively stretch just over 40 minutes, he gives listeners two riff-rollercoaster duos and a 20-minute, chamber-band essay of grim, beguiling beauty. The opener, “Luciform”, is a duo between Diaz de Leon’s electronics and flutist Claire Chase (a recent MacArthur “Genius Grant” awardee). Over the course of its 13-and-a-half minutes, Chase’s flute sometimes often carries the melodic line, while the electronics swoop in big, sine-wave-surfing curves behind her. At other points, Chase’s breathy sound is just a complement to the rampaging crunch of the composer’s programming. The fast switches are what keep the piece interesting. The second duo piece is the album’s title track, and it asks for Joshua Rubin’s bass clarinet to go into reed-squawk mode. (Rubin manages this risky, awkward move with impressive grace.) Later on, the instrumentalist and the pre-engineered sounds partner up for a memorably precise and glitchy passage. The work packs a hell of a lot into nine-and-a-half minutes—so much so that you might need a little bit of a breather. Diaz de Leon has you covered on that count with the album-closing “Portals Before Dawn” (on which he plays synths alongside a sextet of instrumentalists from the International Contemporary Ensemble). The composer tried a similar strategy to close out Enter Houses Of, but this longer, more gradually surging and receding composition gets more out of the composer’s ambient fascinations. Diaz de Leon hasn’t put out an uninteresting release yet, but this compact and wide-ranging album is now the best introduction to his refined feel for instrumental extremity.”
-Seth Colter Walls, Pitchfork
“With Kiasma, the New York-based composer Mario Diaz de Leon brings an interesting twist to his Oneirogen project by amping up the metal elements included on his debut album Hypnos. In fact, the fifty-minute set takes no time at all in announcing that move when the full six minutes of the opening cut “Numina” are dominated by guitar distortion, shuddering six-string textures, and an overall death metal-styled sense of foreboding, desolation, and doom.
But Kiasma is far from one-dimensional, and that’s what makes it interesting. The second track, “Pathogen,” while featuring no shortage of molten guitar textures, counterbalances its metal leanings with sophisticated soundscape design of dark ambient character. Put simply, Oneirogen wisely balances the metal and electronic sides in a manner seldom attempted, and the effect proves to be arresting, especially when drums are wholly eschewed. The album is often epic and grandiose in tone, never more so than during pieces of intensity so great they verge on harrowing, such as “Mutilation” and the album’s centerpiece, “Katabasis,” which finds Oneirogen’s lethal chords lurching like some diseased monstrosity across blasted ruins for fourteen doom-drenched minutes. At album’s end, “Mortisomnia” changes things up by adding Mario Diaz de Leon’s vocal growl to the tune’s guitars-and-synths landscape.
Yes, Kiasma is heavy, of that there’s no doubt, but it’s also refreshingly different from the norm. It’s rare indeed to hear someone, as Oneirogen does, using multi-layered guitar shredding to craft nightmarish dark ambient set-pieces. Doom-laden material never sounded as musical as it does here.”
-Textura
“Like Philip Glass dabbling in trance music, opener ‘Oneirogen’ surges forth powered by intricately arpeggiated synths, tossing the listener around in relentless bursts of colour. The inhuman programming brings a great intensity, flinging the melodies forward at speeds beyond even the most dexterous pianists. From here, it’s clear that Hypnos is constructed of two distinct tones: one dense and dark, the other light and airy. The guitars and electronics will switch places between these roles at whim, yet both sections are so processed and contorted that they often appear indistinguishable. It’s this unpredictable interplay that makes Hypnos such a thrill and every composition as vital as the next, a rarely seen trait among the noisier echelons of electronic music. – Lurker’s Path
“There are moments of artificial ethereality, where plasticized washes of synthetic sound recall the antiseptic calm of new age music, but they’re routinely upended by rapidly pulsing arpeggios, extreme lower-register growls, and rudely distorted, striated tones. Diaz de Leon nods to low-rent horror-film soundtracks (a la John Carpenter or Goblin) but also incorporates whiplashing bursts of power electronics and the ambience of doom metal—all of which wafts, rips, and splatters through these drifty instrumentals. “Faithless” opens like a Tangerine Dream outtake from Risky Business, then suddenly takes a satanic-sounding detour, only to return to a kind of weird calm, like a post-nightmare awakening. Diaz de Leon’s real accomplishment with Hypnos is the unexpected directions the pieces take—they hit you with one surprising shift after another, without ever sounding haphazard or goofy.” – Peter Margasak, The Chicago Reader
“Electronics have been part of classical music since at least the 1930s, the conservative programming of most mainstream presenters notwithstanding, but aside from Iannis Xenakis I can’t think of a composer who’s pushed harsh noise like young New Yorker Mario Diaz de Leon (he also plays in an experimental metal band called Mirrorgate). On last year’s fantastic Enter Houses Of, he juxtaposes relatively conventional lines played by acoustic instruments—some of which are quite lovely—with abstract electronic sounds that can be confrontational, even brutal. On “Mansion” the gracefully twining alto flutes of Claire Chase and Eric Lamb are surrounded by sputtering low-frequency digital pulses, haunting waves of ambience, lacerating bursts of synthetic shrieking, and explosive drumming by Nathan Davis that alternates between ceremonial gravitas and psych-rock fury. On “The Flesh Needs Fire,” Chase and clarinetist Joshua Rubin engage in swooping, acrobatic interplay while electronic noise builds in force, density, and nastiness. Diaz de Leon’s writing for acoustic instruments tempers dissonance with flashes of serenity, and his rhythmic sensibility likewise balances frenetic intensity with near stillness. The electronic element of his music is much more than merely decorative—it’s fully integrated, and alternately jostles, caresses, and dominates the other voices.”
-Peter Margasak, The Chicago Reader