Cyber Monday is officially upon us. The online version of retail's Black Friday finds some of the biggest web-based stores offering drastically reduced prices on music from bands such as Led Zeppelin and the Rolling Stones, among many others.

In many cases these mega-deals are only offered for specified periods of time. For example, between 8 and 10 AM EST today (Nov. 28), you can grab the super deluxe five-disc edition of the Stones' 'Exile on Main Street' for $73.99, almost half off the regular price, at Amazon.

If you got up too late to catch that deal, you can still get almost a third off the price of Zeppelin's four-CD self-titled career retrospective box set -- although, we'll once again advise you, the idea is to own all of the Led Zeppelin records -- when it goes on sale for $32.99 between 10 AM and 12 PM EST. Deals on box sets from Queen, Pink Floyd and more will rotate in throughout the day, you can visit Amazon's Black Friday Deals page to see the full hour-by-hour schedule.

Best Buy's also getting in on the action, with special deals on recent two-disc deluxe edition re-issues of famous albums from the Who, U2 and more, and Target is offering substantial discounts as well. So go get some shopping done, and remember to have some spreadsheet ready to pull up in case your boss walks by.