Jam Sessions is a new, digital musical instrument that is every bit as innovative as Toshio Iwai's Tenori-On, with the added benefit of making sense to someone other than Toshio Iwai. It is endlessly configurable, ridiculously feature-rich, and easy to operate. It is potentially useful for traveling musicians, but is just as enjoyable for amateurs who just want to mess around and make some impromptu music.
Jam Sessions lets you make noise by holding a direction on the d-pad corresponding to a labeled guitar chord and then dragging the stylus across a bar on the touch screen to strum. Up-strokes and down-strokes sound different, as they would on a real guitar. Developer Plato painstakingly recorded samples of up-strokes and down-strokes for each chord, and the effort results in a startlingly realistic sound, which is just different enough from a real guitar to be interesting. The speed and intensity of your strum affects the volume of the sound, as well. Strumming is intuitive and fun, and sets off some lovely visual flourishes on the screen. A tutorial teaches you how to use this system when you first turn on the game; you can revisit the tutorial at any time.

The main mode of the game is "free mode," which basically just lets you play whatever you want, and even record your performances. Should you desire a little more structure, you can play along to any of 20 pop songs, ranging from Beck's "Jack-Ass" to Hendrix's rendition of "Wild Thing." The songs appear as chord progressions only, providing varying levels of guide information to play along with. It is in this mode that Jam Sessions provides minimal opportunity for you to treat it like a game: each song you complete is marked with a check, and you can (and will have to) replay songs to master them. Rather than being graded by the program, however, it is up to you to decide when you have mastered a song. Despite not being held to any rhythm or accuracy requirements, playing the proper sequence of chords and muted notes at the approximate speed of the original song constitutes a challenge that is very game-like in nature. More evidence that this was considered as a concession to game structure is that the songs seem to progress in difficulty and complexity in the order that they are presented. Beck's "Jack-Ass" is only two chords in a repeating pattern for the entirety of the song, while later songs employ frequent chord changes, varying rhythms and lots of muting (which is done by strumming while not holding a direction).

There are endless options for changing the sound and experience of the game. There are plenty of cosmetic changes like background images and the color and shape of the strum bar, and it is enjoyable to 'skin' your instrument to your liking. The strum bar effects can be pretty mesmerizing. There are also more significant options for customization. You can create your own palette of eight chords out of 120 (plus eight more assigned to the L button plus a direction) and save multiple palettes. You can apply six effects to your sound using simulated distortion, flange, chorus, and other pedals, all with appropriate dials, and even save your preset combinations of such effects. You can alter the direction of your up-strokes and down-strokes, change the manner in which the game registers a muted strum, tune the guitar, and set different volumes for different areas of the screen.

It is extremely difficult to rate this in the same way as we would rate a game. It would be unfair to grade something like this only on "fun" value, since it is every bit as much a non-gaming tool as it is an entertainment device. Musical instruments aren't usually spoken of in terms of how fun they are to play. It's the burden of the DS reviewer these days to be faced with such considerations, and we'll probably . There is no question that original developer Plato has created an intuitive musical instrument that sounds great and is amazingly full featured. Ubisoft, for their part, added significantly to the software in localization, adding important features like the preloaded songs and the recording function. Jam Sessions stands as an achievement in clever use of the DS design, and a testament to a large publisher's willingness to take an unexpected risk.

As for judging whether or not it's worth a purchase, that's also difficult. If you think you'd have a good time playing your DS like a musical instrument, this is absolutely worth your money. If you aren't interested in music, do not purchase this product. While it may surprise interested parties by being more full-featured than expected, it's not going to win over anyone looking for a traditional game or anything other than an innovative way to play music. It is exactly what it seems. It is an astoundingly well-designed musical instrument, with a simple interface, but it is still a musical instrument. One that we find satisfying to play with.

Final Score: 9/10