Netrebko

The quartet is the basic unit of string chamber music. Two violins, a viola and a cello: subtract any one of those, and you’re walking a tightrope. Add further players and the issue is redundancy: you’d better know precisely what you want to do with those additional voices, because otherwise they’ll congeal like cold gravy. When it comes to the string octet – two string quartets fused together – only the 16-year-old Mendelssohn really cracked it, going all out for transparency, daring and youthful verve. The Romanian George Enescu took the opposite approach. His Octet of 1900 is chamber music as epic construction project, wrought from steel, not spindrift. ‘No

In the opera world, you’re never far from a Tosca and last week we had two of them, both brand new. That’s healthy: any opera company with a functioning survival instinct is wise to maintain a stock of solid, revivable Puccini favourites. Critics yawn, academics snipe, but Puccini prevails because the simple fact is that Tosca is a straight-up banger. I took a Tosca virgin to the first night in Cardiff. She hadn’t read a synopsis or done any of those homeworky things that novice opera-goers are told they should do, but which they really, really shouldn’t need to. ‘This is bloody marvellous, isn’t it?’ was her reaction after Act