Even I noticed that Welsh football fans were more excited last week than they have been since 1958, a year otherwise more memorable (to a few) for early works by Berio, Birtwistle and Maxwell Davies. The word “harmonious” has been scattered around freely by sports commentators to indicate the national importance for any country taking part in a World Cup. And yet in Wales, land of song and lusty, melodious renditions of Yma o Hyd, there is a new dissonance too noisy to ignore. Less than a month after Welsh National Opera, based at Cardiff Bay’s Wales Millennium Centre, lost its Arts Council England funding – followed by an announcement on Tuesday that it could no longer afford to tour to Liverpool – another new misery has arisen. Cardiff’s primary concert venue and one of the best in Britain, St David’s Hall is under threat after a takeover proposal from the Academy Music Group (AMG), which operates the O2 Academies and other large pop and entertainment venues. It’s still a proposal, but one with leverage. St David’s Hall, opened in 1982, is currently owned, managed and funded by Cardiff council with support from the Arts Council of Wales. Celebrating its 40th anniversary this year, it seats 2,000 and hosts BBC Cardiff Singer of the World and the Welsh Proms, among other major non-classical events. Its acoustic has been judged one of the top 10 in the world. Ironically – a word allowable here – the hall was opened thanks to a Conservative leader of the city council (a bronze bust of whom is displayed in the foyer). This is the latest in a persistent trickle of attempts to pass this venue to the commercial sector. Once again, the classical world is having to campaign for survival. “Still here,” we chorus, as another fault line appears in the UK’s artistic edifice. The petition is here. Otherwise, the week’s musical pleasures have been mercifully pure. Tease apart the tight strands of Bach’s Goldberg Variations (c.1742), written for harpsichord, and twist them anew into a version for violin, viola and cello. This is what the Russian violinist Dmitry Sitkovetsky did in his 1985 arrangement, made to mark the 300th anniversary of Bach’s birth, as well as to pay homage to one of the work’s supreme interpreters, the pianist Glenn Gould. The effect is familiar yet strange. The aria and 30 variations remain intact, but are now heard as if the lines of counterpoint have been exposed in different colours, the easier to locate and follow. This version is far from unknown, but to hear it live is a rarity. The young and virtuosic Teyber Trio – Tim Crawford (violin), Tim Ridout (viola) and Tim Posner (cello) – using very little vibrato and offering plenty of character, gave a lucid, engrossing performance at St Martin-in-the-Fields. Just as the Goldbergs, in any performance, have a sense of occasion, so too does Messiaen’s Quartet for the End of Time (1941). The circumstances of its creation, written while the composer was a prisoner of war in German captivity, can never be told too often. Everything about its form is unusual, from the combination of instruments – piano, violin, cello and clarinet – to its eight irregular movements. It was performed last week as part of Spotlight Chamber Concerts, held in the beautifully restored church of St John’s Waterloo. The clarinettist Anthony Friend, who devised the illustrious series, was joined by three more top freelance players: violinist Agata Daraskaite, cellist Peteris Sokolovskis and pianist James Cheung. There was a sense of true musical equality here, sometimes in jeopardy when bigger name soloists gather to play this work. The visual impact of a darkened church, with the quartet sitting in a pool of light, matched the vision and intensity, as well as the freshness, of their playing. One good fortune – I can’t instantly think of any other – arising from Covid is that some venues have continued livestreaming, including the pioneering Wigmore Hall. The King’s Singers were live on Radio 3 and on Wigmore’s website. This a cappella sextet, founded in Cambridge in 1968, with several changes of lineup since, has not ceased its musical adventures, subversive and open-minded beneath a honeyed veneer. With bass and two baritones characteristically providing a harmonic foundation, tenor and two countertenors scooping and whooping and noodling above, the King’s sound is immediately distinctive, in any repertoire. Last Monday they sang contemporary works commissioned by them: Györgi Ligeti’s The Alphabet (from Nonsense Madrigals), Joby Talbot’s elegant The Wishing Tree and two world premieres – A Dream Within a Dream, a sensuous, three-part work by the Norwegian composer Ola Gjeilo (b.1978), and Alive by Francesca Amewudah-Rivers (b.1998), a rising star in music and theatre, as performer, sound designer and composer. In this short work, her first for the group, part choral, part pop song, she caught the King’s’ silken, playful idiom to perfection. Star ratings (out of five) Teyber Trio ★★★★ Quartet for the End of Time ★★★★ King’s Singers ★★★★ The King’s Singers’ live stream from Wigmore Hall is available to watch until 19 February 2023. Or listen on BBC Sounds