In 1932 English pianist Harriet Cohen commissioned the best of Britain’s composers – Vaughan Williams, Ireland, Walton, Howells – to produce transcriptions of Bach for piano. The result, A Bach Book for Harriet Cohen, is a true document of its time, no less fascinating for its rather conservative contents. Conservative is not an adjective that could be directed at Angela Hewitt’s 20th-century reinvention of the project however. With composers including Brett Dean and Robin Holloway, and works inspired by Bach alongside straight transcriptions, it makes for a joyously diverse programme; last night it proved that it works every bit as well in performance as on the page.

It's always tough sharing a programme with Berlioz's Symphonie fantastique. Could a promising 21st-century composer and a dream-dance concerto of the early 1930s begin to make the kind of sounds the visionary Frenchman conjured in 1830? Not a chance, especially since Stéphane Denève, who had taken his now fizzing Scots orchestra through Berlioz's explosive masterpiece twice already during their first six seasons together, seemed this weekend to have stripped it down to the classical foundations, worked on every jolt and buffet in the symphony's electrifying string writing and managed to make it sound fresher, if not necessarily more shocking, than ever.

First, an admission. I have a blindspot for the chamber work of Fauré, Saint-Saëns and Ravel. I've tried my best, acquainted myself with the most stirring recordings of the finest pieces, got friends to hold my hand. But I've never been able to shake off the feeling that this French trio are mostly a bit drippy in this repertoire, a bit Watercolour Challenge, a bit I-eat-yoghurt-vote-Lib-Dem-and-faint-a-lot, engaging neither in psychology nor dazzle, all simply treading water. So last night was laser-eye-treatment time. If Steven Isserlis and his clever colleagues couldn't banish my blindness at their Wigmore Hall recital, no one could.

Where is the real Elgar to be found – in his boisterous self-portrait at the end of the Enigma Variations, the warm, feminine sentiment of the Violin Concerto and the First Symphony’s Adagio, or the nightmares of the Second Symphony? No doubt in each of them, and more. John Bridcut’s painfully sensitive documentary hones in on the private, introspective Elgar, the dark knight of "ghosts and shadows", always with the music to the fore. And by getting the good and great, young and old of the musical world not just to talk but to react to the works as they hear them, he may have broken new ground.

A 70-minute song cycle for soprano and violin, the Kafka Fragments is the magnum opus (the irony of its miniature forms seems entirely deliberate) of György Kurtág, a composer known for the inscrutability of his music. His lines arrive at the ears fully armed, unwilling to surrender their meaning. A performance of the Fragments at the Tanglewood Music Festival in 2008 famously drove a musically literate audience from the room, so can Peter Sellars's staged interpretation really offer a more engaging experience? Up to a point.

In the last year of his life he was, as a colleague noted when we learned of Charles Mackerras’s death, the wise old gamekeeper in the spring forest of Janáček's Cunning Little Vixen. No wonder Mackerras, we were told last night by his conductor nephew Alexander Briger, wanted that most ecstatic celebration of the natural order for his memorial, just as Janáček had had it played at his funeral. Was it trivialised by an encore number from Mackerras’s deliciously arranged Sullivan potpourri-ballet, Pineapple Poll? Not a jot, mate.

We have good days and we have bad days. Ian Bostridge, at last night’s concert at the Barbican, was not having one of his better ones. But time and CD releases wait for no man, and so he gamely ploughed through his programme of music written for three great Baroque tenors (no prizes for guessing what the title of the album is – do you think EMI would pass up an opportunity like that?), and by the end appeared a little more comfortable than at what was a rather tentative start.