Ah, the good old days, when sonic philistines debated the merits of vinyl over compacts discs.

This week, Radiohead may well spark a debate over FLAC versus AAC that could bring a misty eye to audio historians. Radiohead's new release on Tuesday isn't about alphabet soup. Rather, the band is offering fans, via a London company called 7Digital, their first chance to download is latest album, “The King of Limbs,” in higher-quality digital formats.

FLAC stands for free lossless audio codec and, at 24 bits, is said to feature the same audio fidelity in which bands record their songs. In the mastering process, when recordings are made ready for copying on to CDs, the accuracy is taken down a notch, to 16 bits, a process that has annoyed recording engineers and bands because some of the nuances of their music can sometimes be lost.

But the losses are minimal when compared to what happens to music files when they are compressed into downloadable formats such as MP3 and AAC, which stands for advanced audio coding. These formats were spawned in the 1990s to allow listeners to squeeze more songs onto devices such as the iPod, which debuted in 2001 with a whopping 5 gigabytes of memory. That was enough to hold "1,000 songs in your pocket," according to Apple honcho Steve Jobs, but only if they were aggresssively compressed.