Professor Bad Trip is Fausto Romitelli's inebriating, mind-bending magnum opus. Electric guitars fresh out of Captain Beefheart collide with miked up winds and strings. Stacks of speakers churn out a juicy, dirty mixture. To experience this particular synthesis of psychedelic rock and spectral music was to be sucked into Romitelli's inner-world, only to be spat out again at the other end of the universe.

This was the culmination of the 23rd edition of Milano Musica – the city's annual cocktail of contemporary music – in which this year's programmes have placed the works of Romitelli amongst those of historical and contemporary influences. Tonight's farewell toast was unveiled at the Studio Melato, where the iconic Teatro Piccolo places the more experimental end of its output. A portion of the audience sprawled on cushions in the theatre's hollow. There was a buzz about the place, and levels of anticipation were high.

Romitelli graduated from the Conservatorio “Giuseppe Verdi” di Milano, before moving on to studies with Gérard Grisey at Paris's ICRAM. Founded by Boulez at the behest of President Pompidou, the centre soon became the haunt and laboratory of the "spectralist" composers, who subjected sounds to computer-based acoustic analyses in the shaping of strange aural worlds. Romitelli died young, after a long battle with cancer at the age of 41, but his legacy displays a voice that was by then well-fleshed out. Sound is “a material to be forged”, posited Romitelli, and the composer sculpted it visionary ways.

Professor Bad Trip (2000) takes its cue from a psychedelic mix of 1960s literature, where beat Generation's Allen Ginsberg advocated the use of LSD alongside Dr Timothy Leary, and William Burroughs' heroes went on drug-fuelled journeys through Afirca and America. A cover sheet ackowledgement in Romitelli's score points to Henri Michaux's ecstatic Misérable Miracle, where the French poet explores the “space within” having taken six times the usual dosage of mescaline. 

Tonight's programme notes call forth the original Professor Bad Trip, officially known as the psychedelic cartoonist Gianluca Lerici, in a front cover print of his comic book adaptation Il Pasto Nudo: loosely inspired by W.S. Burrough's "The Naked Lunch". A bespectacled scientist brandishes a suspect injection, and tentacle patterns bristle behind into every corner. 

Matching Lerici for vivacity and audacity, Romitelli's way-out meld of piano and MIDI keyboard, kazoo and water gong, spangles and flexes as it streams through Paolo Brandi's mixing deck. The work's organisation into three "lessons" is an allusion to Francis Bacon's triptychs (and his Three Studies for a Self Portrait in particular) where perspectival shifts see the object morphed in strange contortions. Romitelli's riffs rotate hypnotically, always distorting, always warping, before rough swipes from electric guitar provide a burst of energy, sending fresh sounds shooting in new directions. The process does more than represent a mind-bending trip; it got us feeling vertiginous in itself.

Ensemble RepertorioZero were an absorbing sight under Angelo Linzalata's smouldering lighting scheme. Not short on physical self-expression, percussionist Simone Beneventi was a particular standout as he negotiated his percussive Aladdin's cave with unbridled energy. No conductor was required for this performance, where playing was tight and full of spunk. "Lesson II" nearly sent us over the edge when a cello rigged up like an electric guitar with plenty of distortion weaved an outlandish solo like Jimi Hendrix.

No tribute would be complete without illuminating words from those in the know, so Milano Musica and Mariuccia Rognoni, wife of the late Milanese artist Franco Rognoni, commissioned works from two of Romitelli's closest collaborators. Giovanni Verrando's Krummholz transforms string ensemble into a percussive cacophony, where metal-capped fingers patter their instruments' bodies in a dance that evokes Romitelli's pulsing rhythms. "Riccardo Nova recalls living with Romitelli in Belgium apartment, and on being sent away by the dosing composer when bringing him his morning coffee because he was "working" on Professor Bad Trip. Nova's Yagé Howl effectively summons that dreamy middle-ground with music that massages with waves of sound. Light flooded the stage for these meditations that split the panels of Romitelli's triptych, effectively snapping us out of his overwhelming world and into a more reflective state.

Milano Musica's great triumph has been to put this under performed music firmly on our radar. The groundwork has been laid with six weeks of talks and concerts, but Romitelli's fascinating oeuvre remains one to be explored.