Gabrieli Consort & Players/Mccreesh | Barbican, London

"Saget, saget mir geschwinde, Saget wo ich Jesum finde, Welchen meine Seele liebt!" "Tell me quickly, where I shall find Jesus, whom my soul loves?" The Easter round of Passions, Messiahs and Stainer's Crucifixions - lent added impact in the 250th anniversary of Bach's death by ENO's staging of the St John Passion - often sees a curious omission: Bach's Easter Oratorio. The work dates from 1725, that fertile period immediately following his arrival in Leipzig which witnessed - like matching high points in the careers of Dürer or Cranach or Filippo Lippi - the genesis of masterpiece after masterpiece.

It's a glorious outpouring: light-stepping, rapt, compact (a mere 45 minutes). In his preface to the Gabrieli Consort and Players' concert on Sunday, Paul McCreesh caught the spirit of the piece: this oratorio is "exhilarating', an outpouring of visionary rapture as sustained as the widely performed Magnificat (composed for Bach's first Christmas at Leipzig and restructured a decade later) with which McCreesh prefaced the Easter work.

How better to pass an Easter Sunday evening? The Barbican Hall was packed to the gills - a tribute to the accomplished Gabrieli performers as much as to the twin pull of Bach and the deity. McCreesh began as he meant to go on: the vivid sinfonia from Cantata No 42, composed at the same time as the Easter Oratorio and first heard exactly a week later, on Low Sunday 1725. Lutheran and Catholic church music in 18th-century Saxony were already heading for a high, but little can have prepared the St Thomas's or other local Leipzig congregations for this onslaught of spiritual genius.

Unadulterated excellence is what the unsubsidised Gabrieli Consort is all about: even the small two-to-a-part choir with which McCreesh performed the choruses (he plans to record it with single voices) seemed to savour every moment. Yet part of this was to do with the jointly-imposed restraint. How many times has one heard flatulent, over-egged performances of the Magnificat which might have suited a local Rathaus bunfight, but bore little relation to the text?

Not one of the five soloists overindulged. Julia Gooding set the tone with "Et exultavit" - gorgeously reined-in, more girl-than matron-like (the Virgin Mary was, after all, a teenager), and employing the voice more as an additional instrument than the kind of emotionally illiterate, bravado display one commonly encounters. Here was a young girl, to poach CS Lewis's phrase, "surprised by joy". With her minimal whisper of a shy vibrato the young American, Kimberley McCord, sounded strikingly close in the Magnificat to one of Bach's boys, albeit a little maturer in the third Mary's extraordinary aria "Seele, deine Spezereien" - here the centrepiece of the Easter Oratorio, and an undoubted showstopper. It was this kind of ingenuous approach that brought Emma Kirkby to the fore over 20 years ago. Likewise Neil Davies's nimble touch in "Quia Fecit" - as in his brief but telling recitative ("Wir sind Erfreut") as the oratorio's St John - brought a gorgeous poise. The soloists skimmed Bach's notes like zither-playing gazelles.

If the Gabrieli's unsupported upper string playing was inspired, and the brass section's command of their serpentine early instruments breathtaking - the trilling in the opening Sinfonia's recap, for instance - it is in the solo wind, which McCreesh often has the unassuming confidence to leave unconducted, that Bach reveals the work's soul, much as it sears through the obbligato viola da gamba in the St Matthew Passion.

There is a kind of duende - a rich, dark, human undertow - to his oboe, flute and twin recorder obbligati. In the opening recitatives - shades of the St John Passion - the oboe sighs, or soughs; the rocking strings and reflective recorders of Paul Agnew's tenor aria ("...mein Todeskummer nur ein schlummer") literally slumbered, its imagery as graphic as a Berlioz or Britten operatic nocturne.

But what galvanised the audience most was the fast-shifting oboe underlay to Mary Magdalen's rapturous self-abandonment. The wonder, the eagerness, the high-riding optimism ("komm, umfasse mich" - "come, embrace me") are just what the alto, Robin Blaze, does best. Blaze sings each note with the thrill of a child finding a new toy - no wonder it emerges with burnished beauty and brilliance.