Every now and then, people send us questions on the "Contact" form: most frequently, these take the form "How do I find a recording of Schnabel's 1941 concert at Carnegie Hall" or "Where can I get a recording of Richard Drigo's Harlequinade". We do our best, which usually means searching on Amazon, Archivmusik and a few other selected sites, although I'm not terrifically sure why people expect us to know the answer or to do their research for them.

Just recently, however, we've come across an truly extraordinary resource for finding obscure recordings - not to buy, but to borrow. It's in the form of "Worldcat", a US based venture which aggregates library catalogues and is believed to be the world's largest bibliographic database.

Clearly, Worldcat won't help you buy a CD. But it will enable you to find out what exists, going back an awfully long way in time - and if you're lucky, it will identify a copy that you can go and access in a library near you. The process is simple: you go to www.worldcat.org, and type something like "Artur Schnabel Carnegie Hall". Narrow down the categories to "Sound recording" and you will get a list of CDs, LPs, tapes and anything else that matches your keywords in any participating library - which includes a large number of the biggest libraries around the world. You'll find a stack of recordings in existence that you would have no idea of. (In the example I've given, the 1941 concert went unrecorded, but you can find other recordings of Schnabel from the period).

There are some limitations. You often get a large number of listings for what turns out to be the same item: this happens because there's no universal unique identifier for a CD in the way that there is an ISBN number, so Worldcat can't deduplicate its listings. And if you're specifically trying to find an item near you, it can be frustrating: Worldcat requires you to find the item first, and only then will it give you the chance to find which libraries the item is in - annoying if you have several dozen entries to look through. And of course, the whole thing is keyword-based, so if you want to find performances BY Stravinsky, you can't: they're mixed in with performances OF Stravinsky's music.

Still, if you're serious about finding a particular piece of music, this is an extraordinary resource. And if you're a fan of star performers from bygone ages, you can have fun just browsing to see what exists (opera fans can try searching for Mario Lanza or Nellie Melba).

David Karlin 3rd February 2010