Play the guitar in time and properly. There's various ways to play the game, explore it and select the one that you prefer.
In the MUSIC MODE, interact with the mouse or with the A-S-D-J-K-L keyboard keys to compose your own music. In the NOTE MODE, there's 8 notes per line and you have to play one by one (to play them use the A-S-D-J-K-L keys); the game shows 8 letters and you have to repeat the sequence and press the space bar before the time limit. In the SPEED MODE, the notes are falling and you have to press the corresponding key (always with the A-S-D-J-K-L keys) when they pass by the staff line: each note you miss is an error, and you lose after 50 errors; your goal is to keep playing during 5 minutes, and there's 5 levels of increasing difficulty. In the SOUND MODE, you have to play the notes you hear: 5 notes will be played, and then you have to press 5 keys from the A-S-D-J-K-L group to reproduce the sound sequence; even if you're not a musician and don't know the notes, you can do it after some time of trial and error. In the MEMORY MODE, you play a classic game of memory, with 16 pairs of equal cards that you pick with a click.