In the immediate aftermath of the 9-11 attacks, music presenters struggled to readjust programmes so that they could provide an appropriately solemn response. For some this seemed the only justification to enjoy music at all in the face of nightmarish reality. But the act of making music with care and conviction is itself life-affirming and humanity-empowering, as Leonard Bernstein knew when he famously declared: "This will be our reply to violence: to make music more intensely, more beautifully, more devotedly than ever before."

Ludovic Morlot movingly quoted those words before leading the Los Angeles Philharmonic in its first-ever performance of Become Ocean. But it was the music by John Luther Adams that brought home the message most needed, as had the account of Beethoven's Violin Concerto with soloist Sergey Khachatryan in the programme's first half. For those of us on the West Coast reeling from the recent news of the back-to-back atrocities in Paris and in Beirut, the ability of these two composers to construct worlds ordered by beauty – worlds strikingly different and yet intriguingly complementary – seemed almost miraculous.

Morlot was in town to guest conduct the LA Philharmonic in a weekend of concerts, beginning with a programme that had combined the Beethoven concerto with Benjamin Britten's Sea Interludes from Peter Grimes (which I was not able to hear). This was the first of two performances of the Beethoven/Adams programme and provided a fascinating opportunity to witness the French conductor's rapport with an ensemble outside of his home turf in Seattle.

Indeed, the acclaim John Luther Adams' Become Ocean has received since Morlot and the Seattle Symphony commissioned and premiered it in 2013 – it won last year's Pulitzer Prize in Music and the Grammy Award for Best Contemporary Classical Composition – has redounded to their credit. But the friendly, warmly reverberant space of Disney Concert Hall in Los Angeles seemed to encourage Morlot to open up a new vista in his approach to the piece and the focused response of the LA Philharmonic musicians yielded abundant dividends.

Having experienced Become Ocean in the Seattle Symphony's home concert hall and at Carnegie Hall (where the orchestra played it last year), I found that this most recent realization elicited mesmerisingly complex and unpredictable emotions. While the first performances of Become Ocean reminded many (including this listener) of the colours and shifting textures of Wagner's Rheingold Prelude – essentially, in other words, of a play with surfaces – this time the overlapping columns of harmonies seemed closer in spirit to the anguished awareness of Parsifal.

The piano's restless stream of arpeggios, for example, which continues throughout the length of the 42-minute piece, alternately emerged from and sank back into a tapestry of celesta, harps, and gently thundering timpani. These gestures in turn produced a beguiling counterpoint with the differently timed patterns traced by the three choirs into which Adams separates his large orchestra (strings, winds and brass). They guided the ear to varying levels of depth in the field of sound, much as the hovering colors in a Rothko painting encourage a dynamic gaze from the patient viewer.

Become Ocean is characteristic of Adams in the way it uses a highly abstract logic to engage the emotions: far from being divorced from (or indifferent to) the sensual reality of its sounds, the rigorous compositional process here generates an inescapably immersive sonic poetry.

On the other hand, Become Ocean is deceptively simple in that it's easy to fool yourself into thinking you know where the music is "going", since the surface patterns quickly become apparent: series of sustained diatonic chords from the different choirs that are overlaid and then detach, all against the tapestry of roiling arpeggios.

Yet that's nothing more than the "plot summary" of a complex novel, as became apparent in Morlot's unwavering attention to the significance of shifting weights and harmonic colours. This was a performance that beckoned the listener to let go of preconceived templates and expectations and to yield to the music's immersive spell.

Odd as the match of Beethoven with Adams seemed initially, Khachatryan's interpretation of the Violin Concerto displayed a kind of mindfulness that called for intense concentration on the moment – a useful attitude to hold onto, as it turned out, for Become Ocean. The 30-year-old Armenian virtuoso is justly celebrated for the exquisite, refined beauty of his sound, and he left no vein of the concerto's lyrical riches unexplored.

Morlot's restrained tempi afforded ample room for Khachatryan to sustain his supremely poetic and contemplative approach, which almost suggested an act of devotion in the Larghetto. If a sense of the bigger picture became a secondary consideration, especially in the first movement, which seemed to linger in its own "heavenly lengths", the beauty of Khachatryan's phrasing stirred the soul.