In true "flash mob" form, Arista won't reveal precise times or places for Lavigne's appearances until 48 hours before each event. (The secrecy is meant to build excitement for the new record, according to the spokeswoman.)

The secrecy also will help build a fan database. Those who wish to be notified about the concerts must provide their e-mail addresses at Lavigne's Web site (www.avrillavigne.net). They'll receive an e-mail or, if they choose, an automated voice mail message with the time and location of the free concert. Of course, details also will be announced on radio stations and on AOL's Digital City Web sites.