First heard on Wednesday, Mothers Shall Not Cry is the third Prom commission from that master of the large-scale modernist sound fresco, Jonathan Harvey: a natural choice for a "millennium cantata" based on world religions. Yet this composer's celebrations of the inner life of the spirit sometimes embroil him in all-too-corporeal manifestations of the essentially reflective.

First heard on Wednesday, Mothers Shall Not Cry is the third Prom commission from that master of the large-scale modernist sound fresco, Jonathan Harvey: a natural choice for a "millennium cantata" based on world religions. Yet this composer's celebrations of the inner life of the spirit sometimes embroil him in all-too-corporeal manifestations of the essentially reflective.

The new work, which is described by Harvey as "a latent opera", involves two main protagonists. A solo soprano (Susannah Glanville) embodies the "divine mother", and the composer's belief that 21st-century society must move away from masculine values.

These values are in turn represented by the solo tenor (Robert Brubaker), a "warrior" figure who appears some 20 minutes into this 38-minute work, dressed in rags, high up in the hall's circle area. Singing in an invented language of Harvey's own, he subsequently descends the auditorium steps, blindfolded and brandishing a sword; the blindfold is removed by the soprano in a concluding ceremony of enlightenment. In frilly white, complete with tiara, she looked, as my companion put it, "like a dessert".

Against these evident odds, however, Harvey's settings of texts from a variety of spiritual traditions - Buddhist, Christian and so on, plus much initial chanting of the names of victims of oppression - frequently transcend the visual circumstances. Adding a female chorus and semi-chorus (from the BBC Singers and New London Chamber Choir), a fairly modestly-sized orchestra and some sophisticated electro-acoustic technology, he provides elegant, often compelling music which ranges from simple chanting and mysterious, evocative polyphony to some marvellous moments exploiting both the timbral and the spatial opportunities afforded by the electronics.

The work's beginning (large wooden "whips" played from each stalls entrance and around the hall's lower corridors) and ending (when the entire forces, except for the two soloists and female chorus, leave the stage) are both simple and strong. The conductor Jac van Steen (a name new to me, making his Proms debut), the BBC Symphony Orchestra and the sound design team, as well as the singers, did Harvey credit.

In addition, there was beautifully moulded and melded playing from Joshua Bell and Steven Isserlis in Brahms's Double Concerto for violin and cello, plus two Bach Preludes and Fugues for organ: one neat (played by Martin Neary on the Albert Hall monster), the other as splendidly shaken and stirred for large orchestra by Schoenberg.

No regrets in giving only brief mention to Sunday's generally disappointing accounts of early 20th-century repertoire by the Gustav Mahler Jugendorchester under a Pierre Boulez who seemed on autopilot, with Petra Lang a most unsubtle mezzo. But it's frustrating not to have more space to praise the Royal Philharmonic Orchestra's first-class Prokofiev (including the most captivating performance of his Classical Symphony I can recall) and Shostakovich (a searing rendition of the First Violin Concerto by Vadim Repin). Everything good you've heard about this band's rejuvenation under Daniele Gatti appeared, on Tuesday, to be true.