The "Band" plays on in this follow-up to the chart-topping, peripheral swapping Rock Band. Once again up to four friends can jam together on drums, lead vocals, guitar, and bass as they choose from a number of licensed songs from rock's biggest artists. The "World Tour" mode from the first game expands to new venues and now includes the ability to embark on a solo bass tour in addition to gigs with the other instruments. This mode is also no longer as restrictive, allowing friends to join in or leave at any time, custom characters to switch instruments, and more.<br><br>Perhaps the biggest new addition for competitive musicians is the "Battle of the Bands" mode. Various challenges are continuously updated online that involve testing your rhythmic skills in themed events. These could involve trying to break a high score on a particular song, complete a series of riffs, and so forth. Bands will be able to see the target score to beat from another band and can continue to play a particular challenge until it's mastered. Challenges will disappear over time as well, with some lasting mere minutes or more difficult ones appearing for months.<br><br>Other new features include more character creation items, from faces and costumes to accessories and piercings, a jukebox option, a revamped "Tutorials" mode with in-depth drum training, and more. Rock Band 2 owners can use the same peripherals introduced with its predecessor, or they can upgrade their gear with the all-new bundle. Refinements to the equipment include velocity-sensitive drum pads, metal-reinforced kick pads, softer button clicks, more responsive strum bars, and support for expansion slots for add-ons like cymbals.<br><br>Rock Band 2 ships with an 84-song library and offers the option to import tracks and downloaded content from the original Rock Band. Featured tracks include "White Wedding Pt. 1," "Kids in America," "Everlong," "Ace of Spades," "Any Way You Want It," "Pinball Wizard," "Aqualung," and "Ramblin' Man." Making their music game debut are legendary artists AC/DC and Bob Dylan. As with the original title, Rock Band 2 supports individual track and album downloads to expand your interactive music library.