Proms: Handel: Semele; Tan Dun: On Taoism, Orchestral Theatre II Royal Albert Hall, London

Monday's Prom, a memorable account of the the oratorio Semele given by William Christie and Les Arts Florissants, was the latest fixture in what is surely proving a perfect summer for lovers of Handel's music. Conducting the work at the Lufthansa Baroque Festival some months back, Ivor Bolton chose to stress the score's strands of character development, chiefly in the figure of the scheming Juno. This performance took up the theme, mezzo Kathleen Kuhlmann's goddess vocally not quite right for the role, but full of theatricality. Into the part of Semele herself, a flat-as-cardboard character, soprano Rosemary Joshua poured so much life and feeling that the music was several times interrupted by spontaneous applause, and no wonder: the liquid embellishments to her Act 3 aria "Myself I shall adore" were as fluent as a nightingale.

Other vocal roles were equally well taken, the singers at home with Christie's sharp tempi and shapely phrasing. Though not the ensemble's debut at the Proms, this was their first time in the Albert Hall, and they coped admirably with its open space. Soloists and choir alike sang without music. Did Handel ever hear it performed half as well as this?

A power cut at last year's Proms blacked out Chinese composer Tan Dun's Orchestral Theatre II. This year's attempt at a London premiere occurred on Wednesday - the day of the tube strike. If Tan believes in the powers of Feng Shui, or the oriental art of building according to the luck of geography, he may be wishing the Albert Hall had been erected in South Ruislip.

The double handicap was all the more telling because he's that rare kind of figure, a composer who likes his audience so much that he wants them to join in with the music. No, we're not talking community song sheets here, but six short nonsense syllables. After a quick "on air" rehearsal led by the composer, the Promenaders were ready to sing along with these sounds in imitation of mystic Tibetan chanting. Around the auditorium, wind players from the BBC Scottish Symphony Orchestra in this, the first of its three 1996 Proms, played and vocalised while their on-stage colleagues hummed, murmured and flapped the pages of their scores. At one point, watching Tan Dun and Martyn Brabbins, John-Cage style, conducting silence, they were also involved in throwing off wild atonal textures that partnered deep incantations from bass Stephen Richardson and vocal contributions from the joint conductors.

But the musical point, or so it seemed to this strikebound Radio 3 listener, was a fantasia on one note: a sustained, chanted, repeated and embellished D. This was not any old D, mark you, but D as Re, the "drop of golden sun" Ray, and suffix of rebirth, re-creation and renewal. Ironically suited to this second attempt and to the season's theme of creation, it also suggested a philosophy of ecological awareness. The English signifiers for sun and moon were prominent in the vocabulary of the piece, and the composer's interval talk with Brian Morton, a bonus for those at home, elaborated on this theme and Tan's desire to make modern ritual from the blend of East and West.

His potential to reach this goal was shown in the London premiere of On Taoism, a major score from 1985 that blends Western orchestral sounds with memories of Taoist ritual singing. Tan was his own eloquent performer and conductor in this powerful reading, slower and more spacious than the orchestra's CD recording, with timbres of contrabassoon and bass clarinet alive and speaking.

In contrast, Ritual Theatre II sounded unfulfilled, though the audience clearly enjoyed the novelty of its role. Tuning in halfway, you might have guessed it was a 1960s revival. Orchestral Theatre III, set for Huddersfield this autumn, promises to give that special decade the multi-media treatment. Be prepared.

Elsewhere in this lengthy Prom, Lars Vogt gave a compact, endearing account of the Schumann Piano Concerto, prefaced by Hamish MacCunn's miniature tone-poem The Ship o' the Fiend. Conductor Martyn Brabbins rounded off this evening of music from many nationalities with Walton's Second Symphony, a beaker full of the warm south and, in his experienced hands, a welcome revival of a major, yet still neglected, symphonic study.