Surface indications suggested that this wasn’t an Edinburgh Festival concert, but a course of university lectures. At least the early music groups Dialogos and Sequentia realised they needed something snappier than “The Carolingian ‘Globalisation’ of Medieval Plainchant”, the event’s tagline and theme. Yet were we downhearted?

No! For Wednesday’s packed early evening programme generated the kind of musical joys and uplift that you don’t easily forget. The moment that the applause was over, patrons bunched round the CD table like Pooh desperate for the honey pot. But no CD could capture the thrill of watching eight gentlemen and Katarina Livljanic pitch themselves with fervour and clarity upon the long hypnotic strands of 9th-11th century plainchant – the holy spaghetti without which no liturgy in the Roman Empire was complete.

Some of the concert’s material praised God with an unbending, impersonal grandeur. But the farther from Rome the original chanting monks, the quirkier their worship. As superbly sung by Benjamin Bagby, Was liuto filu in flize, cast in Old High German by an Alsatian monk, almost carried the force of a music-hall song. The sacred and secular equally fused in Christus vincit, the clamorous finale to a compelling, perfectly executed programme. Catch it on August 23 on Radio 3.

After such minimal splendours, the teeming musicians and Old Testament plagues of Handel’s oratorio Israel in Egypt in Usher Hall came as a shock. Not a greatly stimulating one, either, in Emmanuelle Haïm’s hands. Though her musicians weren’t short of passion – they were the Edinburgh Festival Chorus and the Scottish Chamber Orchestra, after all – this sometimes overesteemed conductor dispatched the score too clinically. She is not a natural Handelian.

The orchestra, choir and most of the soloists did their best to stir our spirits. The sopranos Lucy Crowe and Claire Debono duetted sweetly, there was counter-tenor magic from Robin Blaze, and Matthew Brook gave us the old bass fervour. Top marks as well to the plague of flies.