A COUPLE of months ago your correspondent visited the Library of Congress's Packard Campus for Audio-Visual Conservation near Washington, DC. The facility, converted from a former Federal Reserve strategic currency cache, has millions upon millions of items stowed in underground, temperature-controlled vaults, including wax recordings made by the Victor Talking Machine Company in the early 1900s; lacquer ones, including a trove of NBC Radio shows recorded directly from the engineering booth from the 1930s to 1970s; metal master and "mother" (pressing) discs; as well as innumerable commercially produced shellac and vinyl records. The library's boffins are busy converting analogue formats to modern, digital ones, hoping to do so faster than material degrades to become unplayable. Paradoxically, modern artists are taking their digital recordings and etching them to new LPs.

Vinyl has seen a resurgence over the past few years, and that trend has continued. Nielsen Soundscan, which uses retail data and excludes albums sold directly by bands, found that 2.8m and 3.9m were sold in America in 2010 and 2011, respectively. It expects sales to rise to 4.7m in 2012. This is a far cry from the 300m copies shifted a year in the 1970s in America alone, but a significant uptick from a mere few hundred thousands in the CD-mad mid-1990s. Turntable sales, which declined slightly for the last decade, ticked up slightly in 2011 compared to 2010, to 54,000 units a year. More ancedotally, it is easy to find reports of record stores with new and used vinyl expanding stock and sales; Babbage has seen two in the last few weeks in regional newspapers.

CDs, meanwhile, have plummeted from 600m sold in 2005 in America to well under 200m expected to be purchased in 2012. CDs still make up 61% of albums sold as of June 2012, with the rest coming mostly from digital downloads (which will total 125m for the whole of 2012). This excludes individual digital tracks, which are on track to exceed 1.5 billion this year in America, up from 1.3 billion in 2011. The death of the album format also seemed premature, as the preicipitous drop in album sales as buyers shifted to individual songs flattened over the last three years.

In November the Beatles' first 12 albums were released as stereo LPs from the same digital masters used to produce digital downloads (and the latest batch of CDs). Next year, the LPs will be released again, this time in vibrant mono, something much awaited by audiophiles. Babbage's 22-year-old cousin, who works in a record shop in Olympia, Washington, told him recently that her contemporaries plump almost exclusively for vinyl. The only time they buy a CD is as a gift for a parent or another senior citizen. Her all-women band of punk rockers called The Hysterics offer their music for sale after concerts on seven-inch 45s and cassette, but not on CD.