WHILE Samson, Saul, Jephtha, Israel in Egypt and other English oratorios by Handel tell Old Testament stories, Theodora, recently heard at the Town Hall, Birmingham, and the Barbican, in London, performed by the English Concert, conducted by Harry Bicket, is the only one - if you exclude the hybrid Old and New Testament Messiah - that dwells on an exclusively Christian story, taken from the early centuries of the Roman Empire.

It explores the martyrdom of a Middle Eastern princess, a leading member of a Christian cell during the persecution unleashed in the East in 303-04 by the Emperor Diocletian, not ten years before Constantine declared Christians' freedom to worship unmolested.

Handel was aware that it might not have the appeal that tub-thumping colossi such as Judas Maccabaeus had enjoyed. And, indeed, it enjoyed minimal popularity (just three performances) at the time; but the composer clung to his affection for the work, and a remarkable (and grisly) staging by American director Peter Sellars, first seen at Glyndebourne in 1996, did much to heighten interest in this once unfashionable oratorio.

With good reason. The solo writing is vital and dramatic, and even the chorus - which here was the Choir of Trinity, Wall Street, an American ensemble so vital and rhythmically adept that it contributed some of the best things of the evening - has, as Sellars perceived, music of compelling power and beauty.

While one of the arias that did catch on, "Angels ever bright and fair, Take, O take, me to your care" is reserved for the title role (here sung by the soprano Rosemary Joshua), almost all the most affecting vocal music is shared between two alto roles: Theodora's soldier fellow-Christian, Didymus, and her supporter and ally, Irene.

Here both roles were taken by marvellous singers. The mezzo Sarah Connolly, gloriously on form, was utterly melting in everything she sang - not least the Act II aria, 'Thou art the light, the life, the way", a sensationally moving composition; her duet with Ms Joshua also shone.

Her rival for the honours here was the countertenor Tim Mead: always a sensitive, though once perhaps too recessive, voice. Yet, now, every time he sings, one is on one's mettle: it has become a thrilling sound, delivered with a panache and certainty to match any of his rivals. Mead's growth and transformation contributed hugely to the success of the oratorio: "Kind heaven, if virtue be thy care" at the end of Act I, with attractively skedaddling violins, was an aria of breathtaking beauty, clarity and precision: the moment when Handel makes Didymus determine, if necessary, to die for his Christian faith. 

AT SYMPHONY HALL, a stone's throw away, the conductor Edward Gardner and the City of Birmingham Symphony Orchestra, of which he is Principal Guest Conductor, rounded off their Mendelssohn series (including a superbly spacious Reformation Symphony, now recorded on CHSA 5132, with the composer's Second Symphony, Lobgesang or Hymn of Praise.

The singing of the CBSO Chorus, one of the most polished in the land, was predictably fine, although so was that of the CBSO Youth Chorus who performed two rare Mendelssohn Latin motets - the second, Surrexit Pastor Bonus, quite substantial, with some enchanting solo, duet, and quartet singing.

But while the key to everything was the orchestra under Gardner's watchful and pleasingly unexaggerated beat - the results were riveting, the pacings beautifully thought through and the various desks meticulously together - and two sisters, Sophie and Mary Bevan, matched each other perfectly in "I waited for the Lord", the hero of this Lobgesang was the tenor Benjamin Hulett, whose handling of recitative was as perfect as his dynamic role in the dramatic "The sorrows of death" ("Watchman, will the night soon pass?"), from Isaiah 21. J. Alfred Novello's 19th-century translation - he had succeeded to the helm of the family music-publishing firm in 1829, aged just 19 - still stands up as well as ever.