Relatively recent tweaks to the abundant London concert scene have resulted in top-end events right up to Christmas. We have in part to thank the seasonal festival at St John’s Smith Square, postponing the Orchestra of the Age of Enlightenment’s holidays, putting them together with superb soloists and choirs, and serving up major Handel and Bach. One snag: their Christmas Oratorio when I last went to hear it turned out to be only four cantatas out of the sequence of six.

In 1981 a 20-year-old Swedish trumpeter on national service turned up in the town – city, by Swedish reckoning – of Örebro as soloist in Bach’s Second Brandenburg Concerto. The ensemble, then a mix of amateurs and professionals, some of them from the local military academy, is now the much-recorded and award-winning Swedish Chamber Orchestra; the trumpeter, Håkan Hardenberger, is probably the most famous in the world, and certainly the most adventurous – he still fights for contemporary composers to take first place in musical creation.

The last time I saw Janet McTeer, she was doing her best with the slightly underwritten role of sister to Glenn Close’s lethal Patty Hewes in Damages, the ultimate TV series about the discrepancy between seeming and being. Which is the theme, too, of Christopher Hampton’s Les Liaisons Dangereuses, adapted from Choderlos de Laclos’ peerless epistolary novel.

"Exhibition on Screen" is a logical extension of the recent phenomenon of screenings of live performances of opera and theatre. Initiated with the Leonardo exhibition of 2012 at London’s National Gallery, this is its third season, and the format remains unchanged: a specific show provides the pretext for a bespoke film that goes beyond the gallery walls.

“High Spirits” is a multi-layered title: the caricaturist Thomas Rowlandson (1757-1827) was himself a heavy gambler and a heavy drinker, continually using up his material assets in such pursuits. His high spirits extended to the Georgian society he satirised with such robust good humour; high society and even low society attracted his interests, while he also expended enormous energy detailing political and sexual intrigues.

What is it about Vermeer? Just mention the name and there will be queues around the block. It’s true that there are a handful of other artists with that charisma, but none so rare as Vermeer. The Girl with a Pearl Earring is not only the subject of a recent novel and a film, but also a kind of poster for Holland as a whole, and the star of the recently reopened Mauritshaus in the Hague. At the Rijksmuseum in Amsterdam you can hardly see the handful of Vermeers for the crowds.

Not many people write conspicuously brilliant tweets, but Elizabeth Watts is someone who does. Working on the most demanding aria on her stunning new CD of operatic numbers and cantatas by the lesser-known of the two Scarlattis, father Alessandro rather than son Domenico, she tweeted: “Good news – I can sing 88 notes without a breath. Bad news – Scarlatti wrote 89.”

It was rather like a trip home to see long-lost relatives. Ton Koopman took to the stage at the Liverpool Philharmonic with a broad smile. That smile both greeted the audience and, from what the audience could see, told the orchestra that they were on form. Or, on the other hand, it might have been encouraging them to try harder.

Unswervingly confident, relaxed and assured, the élite of the 18^th century are currently arrayed on the walls of the Royal Academy, gazing down at us with the utmost assurance of their unassailable place in the world, bright eyed and dressed to match. The swirls of public reputation are unpredictable: here is a revelation, the art of one of the most successful and highly prized portraitists of his day, Jean-Etienne Liotard (1702-1789), now almost completely unknown except to specialists.

The city of Brecon (county town of former Brecknockshire, now lost in the spurious and far-flung county of Powys) is a long way from Leipzig and on the face of it has little in common with the home of Bach and the native city of Wagner. But once a year for the past decade this rainy, hill-girt metropolis on the upper reaches of the River Usk has played host to a festival of Baroque music, and particularly Bach, that would match pretty well anything likely to be offered in the Thomaskirche.