ArchivMusic is a real-world test of the Longtail phenomenon. The idea is to take old recordings that are no longer part of the CD catalog and make them available on demand. “Its Web site is now at the forefront of the new burn-on-demand phenomenon that is bolstering classical music sales along with the industry’s great strides in digital downloading. The company’s growing specialty is in reissuing discs that you cannot buy except in a used-CD shop, by burning them one at a time for consumers. It may seem like small change, but it adds up.”