Handel Remixed, Barbican Hall, London<br/>The Bernstein Project, Royal Festival Hall, London<br/>The Damnation of Faust, Barbican Hall, London

Take five composers, think 'bland and commercial', cut and paste a few bars, and call it an anniversary tribute? How depressing

Postmodern pastiche, macho minimalism and childhood memories collided unhappily in Handel Remixed, the opening concert of the Barbican's "Great Performers" season.

In principle, the idea was attractive: take five contemporary composers and invite them to write a response to Handel, to be performed by David Daniels, Harry Christophers and the Academy of St Martin in the Fields together with a selection of Handel's own arias and overtures. Who could resist a Kurtág "Eternal Source of Light Divine", a Sciarrino Concerto Grosso or an Adès "Scherza infida"? Alas, Kurtág (who is published by Universal), Sciarrino (Ricordi) and Adès (Faber) were not approached. Instead, Chester Music, whose idea this was, fielded five of its own composers, with a line-up weighted to the bland and the commercial.

The programme notes were revealing. For Michael Nyman, Handel's music is Kathleen Ferrier on the wireless. For John Tavener, it is a Beecham 78rpm recording of Solomon. For Jocelyn Pook, whose asinine Sing, sing, music was given is based on a chord progression from Saul but quotes liberally from Tchaikovsky, it seems to be the bonnets and broughams of a BBC costume drama. Indeed, of the six works premiered in Handel Remixed, only one showed a real understanding of what it was that was being remixed: the conventions, the techniques, the aesthetic. Craig Armstrong's Themes and Variations correctly identified the timbre and operatic character of the Adagio e staccato from Handel's Water Music, reworking the figures into glassy dissonance, but defused the impact by adding the lyrics to The Communards' hit, "Don't leave me this way", and a melody of Beethovenian contours.

Based on the Queen of Sheba's aria "Will the sun forget to streak", Tavener's Little Reliquary for GFH condensed the original oboe obbligato over a setting of the Pie Jesu text that seems better suited to the spotless bloom of a boy treble than to Daniels's peppery, high-maintenance countertenor. A saccharine string quartet is contrasted with vibrato-free string orchestra, as Handel's (misremembered) motif is slowed and stilled to a tempo even Beecham might have thought too leisurely. In Nyman's arrangement of Ombra mai fu, the original bass line is chopped into chugging quavers for piano with a bish-bosh brass overlay and a graceless descant for flutes and violins. (The trademark bass saxophone was absent but implied.) Nico Muhly's Vocalise on Al lampo dell'armi was a cut-and-paste exercise, all fragmented fioritura and rebarbative trumpet blasts – a technique repeated, at a much slower speed, in his Drones on Oh Lord, whose mercies numberless.

Christophers, Daniels and the Academy of St Martin in the Fields were impeccable in the real Handel and remarkably straight-faced in the worst of the anniversary tributes. But how depressing to discover that music I find endlessly stimulating, endlessly provocative, endlessly now, is, to these composers, an academic puzzle, an in-joke or a Proustian reminder of lying in bed with a thermometer.

Less than 24 hours after the Barbican's GBH on GFH, the Southbank Centre turned on Beethoven. Under Marin Alsop, the combined forces of the Britten Sinfonia, Southbank Sinfonia and Orchestra Europa marked the launch of The Bernstein Project with a sassy, supple account of the overture to Candide and two flower- power tasters from Mass, complete with electric guitar. So far, so good. But how to explain Phil Snedecor's ghastly arrangement of the last section of Beethoven's Ninth Symphony, scored for orchestra, choir, solo cello, the folkband Bellowhead, the Grime-thorpe Colliery Band and two bewildered bagpipers in full ceremonial dress? No stranger to mixing things up in his own music, I suspect Bernstein would have drawn the line at messing with the most recognisable work in the canon.

Order of a sort was restored in Valery Gergiev's fleetingly brilliant reading of The Damnation of Faust with the London Symphony Orchestra. An assault on repertoire that is inextricably linked with Gergiev's predecessor, Sir Colin Davis, might be seen as unwise or impolitic, and there were moments when the ensemble was compromised, the chorus stranded and the speeds dangerously chaotic. Yet Gergiev's realisation of this neurotic, splenetic, fantastical score was thrillingly bold, most especially in the crazed babble of Pandemonium. Stepping in for Thomas Quasthoff, Willard White presented a Mephistopheles simmering with irony and contempt, while Florian Boesch dazzled in the small role of Brander. Michael Schade's stolid, prudish Faust failed to convey any complexity or vulnerability, and was quite wasted on Joyce DiDonato's radiant, candid Marguerite.