From Wikipedia:
Jam with the Band, known in Japan as Daigasso! Band Brothers DX (大合奏!バンドブラザーズDX, Daigassō! Bando Burazāzu DX?, lit. Grand Ensemble! Band Brothers DX), is a music video game developed and published by Nintendo for the Nintendo DS handheld game console. It is the sequel to the Japan-exclusive Daigasso! Band Brothers, which was released at the DS' launch.
Jam with the Band features more than 60 instruments that can be played. Its gameplay focuses on button input similar to its predecessor. The buttons used increases as the difficulty increases - while on the lowest difficulty, any of the buttons may be used to hit a note, while the hardest difficulty usually makes use of all buttons. The notes scroll down at a certain speed, and the players must hit a note with the corresponding button. Up to eight players may play together. It also makes use of the microphone for a karaoke mode that allows players to sing to the lyrics of a song using the Nintendo DS' microphone.