The Theatre of Magical Beings, CBSO Centre, Birmingham ****

An opportunity to celebrate multiculturalism has never been more welcome. Anglo-Indian composer Param Vir has successfully fused Western and Eastern cultures together in his brilliant new work The Theatre of Magical Beings. Not concerned with conventional theatre, it inhabits an interior theatrical space where something magical is revealed and contains internalised encounters with four archetypal mythological beings. There are no narratives, rather a vivid and potent image of the energy generated by these four archetypes.

The first movement, "Garuda", is inspired by a half man, half bird creature from the Vedas. The opening string sextet juxtaposes intense activity with moments of introspective stasis, a microcosm of the piece as a whole. It develops into an ecstatically affirmative celebration, recalling Tippett and Messiaen in its joy and exuberance.

The second movement is named after Uroborus, the ancient European symbol of a coiled serpent eating its own tail, denoting renewal and self-reliance. Slithery glissandi conjure up images of the writhing serpent, while a beautiful oboe line irradiates the score. "Uroborus" is a completely symmetrical structure, paying tribute to the complexities of Indian classical music, precluding neither beauty nor clarity.

"Elephant" comes from legends surrounding the Buddha's birth. This movement is the most powerful and physical of all, Vir using it to emphasise the nobility and majesty of the animal. It is a world away from the low comedy of Stravinsky's Circus Polka ballet and lumbering double basses à la Saint-Saëns.

The final section, launched and resolved by percussion, is named "The Simurgh", after a mystical, griffin-like bird of paradise. According to the Sufi poem The Conference of the Birds, when mortal fliers reach the end of their search for the Simurgh, they see a shimmering mirror of light reflecting themselves – a powerful image of self-realisation. Achieving this musically, two percussionists are positioned at either side of the stage, triggering one another antiphonally and hurling ideas across the musical spaces to thrilling effect.

Written for and premiered by the Birmingham Contemporary Music Group, The Theatre of Magical Beings is one of the group's most ambitious achievements, 25 minutes long and requiring 25 players. Unusually for a contemporary work, the string section lies at the heart of the ensemble and Vir writes especially inventively for them, creating a wealth of exciting sonorities. The lower end of the score's register isb>subtly enhanced by the addition of a contrabass clarinet. Unquestionably one of the finest international new music ensembles currently before the public, the BCMG plays superbly well in this virtuosic and hugely enjoyable, life-affirming work.

The conductor Susanna Mälkki maintains a firm architectural grip, while giving the players freedom to savour the score's many poetic and colourful touches. This is a major triumph for the composer and the Birmingham players, whose Sound Investment scheme continues to enrich the repertoire.