Orchestre des Champs Elysees/Herreweghe, Barbican Hall, London

When contemporary music turned indigestible, early music on period instruments satisfied the appetite for new sounds without having to hang them on modern work. It turned into a movement much like new music, each country spawning its own version. So while the UK watched John Eliot Gardiner move from conducting baroque to classical to a grandly titled French-sounding effort for the 19th-century, in Belgium and France a similar career was building up for Philippe Herreweghe.

Sunday's visit by what looked like the entire Herreweghe fiefdom put the focus on the 19th century, starting with César Franck's Symphony in D minor. No, they didn't play it on an organ. There is no music better suited than the French tradition to the revival of instruments from even half a century ago. Even now, orchestras from francophone Europe make a different sound, but in the past, the contrast with Saxon styles was more extreme.

Herreweghe's Orchestre des Champs Elysées is a strong and highly skilled band that comes across the way that Fifties recordings of the Orchestre de la Suisse Romande might have done, if the playing had been better and the woodwind more old-fashioned. The punchy, bright brass, the lean and sweet violins, the horns with their bite and lyricism, are a pleasure in their own right. They certainly suited the strange scoring of the Franck. It is strange because it is unlike his other orchestral pieces, replacing delicacy with a robust, block-like character. Unkind observers have said you can hear Franck pulling out the organ stops (he had his main career on the instrument), but it's more like emulating the concentrated energy of Beethoven. With modern instruments, it can sound thick, but here, with more colourful wind and less overwhelming strings, it made sense in its own way, most of the time. Credit also goes to careful balancing and well-chosen speeds, though the performance stuck closely to its speeds and lacked fire and romantic flair. Towards the end, even the balance came unstuck, and the flashbacks from across the whole symphony, each at its own pace, were stiff.

Fauré's Requiem, fluent and affecting, sounded like a more practised and digested performance. With the Choir of La Chapelle Royale and the Collegium Vocale Gent, Herreweghe opted for the familiar version with large orchestra – less authentic than the one he has recorded, as Fauré didn't do all the scoring himself and disliked some of it, though he approved of it as the published score. Much of the impact came from using professional singers, who brought a clarity and lack of strain that the British choral tradition rarely delivers. They sang their Latin with rigorously French pronunciation, which lightened the vowels and transformed the sound colour.

Choosing a harmonium instead of an organ looked ridiculous at first, as it made no impact against the strings, but it came into its own in solo passages and especially at the end, when its soft timbre offset the voices perfectly. It also helped keep a sense of intimacy, backed up again by subtle balancing and a set of fine-toned trombones. Herreweghe's sombre, slow-moving conception achieved gravity without ponderousness, and both soloists were ideal. Stephan Ganz's light, vibrant baritone was sometimes covered by forthright strings, Johannette Zomer was a suave, very adult high soprano who still made the Pie Jesu fresh and touching.