Jam Sessions DS hands-on at Gamespot.

"When we first heard about Jam Sessions for the DS, we immediately concocted wild mental images of playing Guitar Hero with a stylus. Depending on how you look at it, it's either a blessing or a curse that the game is about as far from Guitar Hero as a musical simulator can be. Jam Sessions is less game and more music creation tool. The title is based around Japan's Hiite Utaeru DS Guitar M-06 (Sing and Play DS Guitar M-06) but it's had a spit polish, some interface fine tuning (no pun intended), and a complete rework of its song tracklist on its way to picky Westerner audiences."

Full Source: Gamespot