Porgy and Bess, Festival Theatre, Edinburgh<br/>Montezuma, King's Theatre, Edinburgh<br/>Prom 42, Royal Albert Hall, London

Summertime, and the hip-hop is dazzling

Bequeathed to black singers in perpetuity, Porgy and Bess is blessed with great melod-ies: the radiant, hope-filled lullaby "Summertime", the snake-hipped machismo of "A Woman is a Sometime Thing", the subversive syncopations of "It Ain't Necessarily So", Porgy's tragic-ecstatic "Bess, You is My Woman Now".

The gaps between hit numbers are short, the choral pastiche strong. But the characterisation of these "God-fearin' ladies and God-damnin' men" of North Carolina goes little deeper than my thumbnail descriptions of their signature songs. Boil this "folk opera" down to its essence and all that's left is tragic-ecstatic. Serena, Bess, Clara, Jake, Sporting Life and Porgy may be battered by poverty, addiction, police brutality, and disability, but they can still sing. Small wonder that artists who would rather be performing Tchaikovsky or Verdi have a complicated relationship with Gershwin's bequest.

Choreographer-directors José Montalvo and Dominique Hervieu add a little urban grit to Porgy in their Opéra National de Lyon production. As with their staging of Rameau's Les Paladins, video features prominently, while the dancers of Compagnie Montalvo-Hervieu and Théatre National de Chaillot move in hip-hop counterpoint to the music, sometimes lyrically, sometimes in dazzling flurries of break-dancing. Above the shanty-town set, black-and-white photographs of freed slaves fade into images of lynch mobs, the interior of a segregated bus and civil-rights rallies, then the burning cars and graffiti-decorated banlieues of contemporary France.

Synchronised jumping fish, dancing crabs and a blissed-out goat eating strawberries offer relief from the righteous indignation of documentary footage. Crown's murder of Robbins (which takes place behind an upturned table on stage-level) is revealed on screen in gruesome CSI detail, his reclaiming of Bess a startling tableau of athletic buttocks. The most impactful original imagery comes in the storm, as Clara (Magali Léger) is lost to the greedy sprawl of the Atlantic, and in the use of slow-motion close-ups. Sung with shimmering sweetness by Léger, the first verse of "Summertime" is accompanied by a film of a teething baby baffled by pain, the second by the cooing, peek-a-boo faces of its carers, as seen from the baby's perspective. It's a touching moment, mirrored later in the camera's unflinching focus on Serena as she grieves for Robbins, her face distorted with anguish in one of the very few numbers ("My Man's Gone Now") when Gershwin stops being cute.

If Andrea Baker's Serena was the undoubted star of the show, her coppery, Mahlerian mezzo charged with intensity, Ronald Samms's sly, bright Sporting Life came a close second. There can't be many tenors who go from singing Otello to break-dancing in one season. Derrick Lawrence's soft-grained Porgy and Janice Chandler Eteme's elegant Bess struggled to cut through William Eddins's insensitive conducting in their rhapsodic duet. Only in the quieter moments was the musicality of Lyon's orchestra evident, though special mention should go to pianist Wilhem Latchoumia's "Jasbo Brown's Blues". LaVerne Williams's Maria, Gregg Baker's Crown, Keel Watson's Frazier, Luanda Siqueira's Strawberry Woman and Phumzile Sojola's Robbins gave characterful and intelligent support. A bold production of a well-intentioned but troublesome opera.

Written in 1755, to a libretto by Frederick the Great, Carl Heinrich Graun's Montezuma was subjected to the worst abuse in Claudio Valdés Kuri's crazy staging for Concerto Elyma. A mostly young and inexperienced cast grappled with singing while upside-down (Lourdes Ambriz's Eupaforice); singing semi-naked on top of a column (Flavio Oliver's Montezuma); singing while forcing bottles of Coke between the thighs of transvestites (Adrián-George Popescu's Cortes); and singing while restraining a very vocal guard dog (Christopher Carré as Narvès). There were ponchos too, of course, but these were ironic ponchos.

Graun's blameless tragedia per musica contains some gracefully scored arias (almost all in a major key until Act III), many of which were cut in an edition that closed with Luis Antonio Rojas's woozy arrangement of Manuel de Sumaya's motet Albricias Mortales. The voices ranged from petite but pleasant to vinegariness of the sort associated with the production of chutney. Concerto Elyma played in a state of good-natured dishevelment, the natural horns continually startled by Graun's extreme tessitura, the two harpsichordists visibly cringing at Gabriel Garrido's rotary-blade conducting of each recitative, in which 18th-century secco style was replaced by a gurgling torrent of broken chords from the century before.

The BBC Symphony Orchestra's programmes are often notable for their randomness, as though hats marked Rarity, War-horse, Anniversary and New Commission have been filled with folded pieces of paper. On Tuesday night (Prom 42), however, keys, textures and colours dove-tailed magically under Edward Gardner's measured, spacious beat. The concert began and ended with a high A: faint as breath in the opening of Arvo Pärt's Cantus In Memoriam Benjamin Britten, strident and dogmatic at the terrifying close of Shostakovich's Fifth Symphony.

Shostakovich's chill, milk-white doubling of violins and flute, and tugging, lilting misery linked back to Britten's Four Sea Interludes from Peter Grimes, while the cool suspension of single-strings in the lyrical slow movement of Huw Watkins's new Violin Concerto recalled the chastity of the Pärt. Too brass-heavy in the hall for Alina Ibragimova's delicate, fretful tone, the Watkins seemed better balanced when heard via Radio 3's Listen Again, its aphoristic figures clean and clear. Though the BBCSO strings frayed under pressure, its principal flute (Daniel Pailthorpe), piccolo (Rebecca Larsen) and clarinet (Andrew Webster) played with unalloyed beauty of tone.