There are good reasons why people pay top prices – hundreds and sometimes thousands of euros – for classical albums from the 1950s and 1960s on labels like Decca, Columbia and HMV. Obviously, they're scarce, especially for the stereo versions that appeared in an age when mono sound was the norm. Also, these were generally albums that oozed quality, from the music itself through to the quality of the sound. Nothing was left to chance in the golden age of the classical LP. This is the tradition that Challenge now wants to champion by issuing albums on vinyl, says Eric Storm, who's been involved in every step of putting the collection together.

"We're focussing first of all on the audiophile market", he says. "If you have a top notch sound system, you'll really hear the difference. And every aspect has to show that these are unique issues, including the way we present them. They're individually numbered and in limited editions of 1,000. We pay a lot of attention to the sleeve and artwork, and the LP is presented in a paper strip – an obi.  And they come with their own booklet. We take care over every detail."