
If you've already got the Frequency/Amplitude point of reference, you have a good idea of how the gameplay in Rock Band Unplugged handles. If not, imagine you're playing Rock Band, except that there are four notes instead of five, and rather than picking a single instrument, you're free to switch between all four on the fly. Like the Rock Band that you know, there will be overdrive, there will be solos, and the goal is still to try to hit as many of the notes as possible, though when you successfully hit all of the notes in a phrase, that instrument will clear out for a while, allowing you to switch your focus to another instrument. Part of the trick here is that, if notes are passing on any of the tracks you're not currently on, they'll count against your overall band meter. If that sounds too intense, the game will also offer a warm-up mode, which won't penalize you for anything other than notes missed on your current instrument. If it doesn't sound intense enough, then there's the band survival mode, which never clears out any of the tracks for you.

AFI - "Miss Murder"
Audioslave - "Gasoline"
Black Tide - "Show Me the Way"
Freezepop - "Less Talk More Rokk"
The Killers - "Mr. Brightside"
Queens of the Stone Age - "3's and 7's"
System of a Down - "Chop Suey!"
Tenacious D - "Rock Your Socks"
3 Doors Down - "Kryptonite"
Alice in Chains - "Would?"
Blink 182 - "What's My Age Again"
Judas Priest - "Painkiller"
Nine Inch Nails - "The Perfect Drug"
Nirvana - "Drain You"
Weezer - "Buddy Holly"
Bon Jovi - "Livin' on a Prayer"
The Police - "Message in a Bottle"
Jackson 5 - "ABC"
Kansas - "Carry on Wayward Son”
The Who - "Pinball Wizard"
In addition to the 41 songs that will come on the UMD, Rock Band Unplugged will have a fully integrated online music store for you to buy and download new songs. Though Harmonix isn't yet committing to a schedule for how often new songs will hit the Unplugged store, you can expect to see 10 songs available for download the week the game comes out.
It's worth stressing that Rock Band Unplugged really seems to do an ace job of capturing the look and feel of the series, and it looks quite crisp on the PSP screen. I think the changes that Harmonix has made to the gameplay for Rock Band Unplugged makes a whole lot more sense than fabricating some weird peripheral to try and turn the PSP into a tiny instrument. To quote Harmonix's own Alex Navarro "I don't think tiny instruments are cool. Unless we're talking about a ukelele." Frankly, my only misgiving about Rock Band Unplugged is that it's currently only slated for release on the PSP, because I think it could play on a big TV just fine. While Frequency and Amplitude might not have caught on in their time, it seems like music games have finally reached a point where people don't need plastic instruments to know how to rock.