Activision has said that the official Guitar Hero III demo will be on Live Marketplace tomorrow, otherwise known as a day before my birthday.
We say official because earlier we told you that clever, maths-liking folks from Internet had worked out a way for you to download it already, then burn it to disc and play it on a normal, unmodified 360.
The demo builds up to a Guitar Hero III: Legends of Rock Weekend that will offer prizes to fastest fingers, and even let you shred-off against members of the development team.
The competition runs from 2nd to 4th November, and could see you walking away with a limited edition guitar faceplate signed by hairy guitar player Slash.
Activision will be popping the official website for the competition up tomorrow, where you will be able to find a full list of terms and conditions like if you have to be in the US to win, for example.
The publisher also stamped confirmation on the 23rd November date for the PS3, 360, PS2 and Wii versions of the game earlier today, although Aspyr Media is handling the PC version so we aren't sure about that one.
Pop over to our Guitar Hero III: Legends of Rock gamepage to for all sorts of information about the game, like why it should be very good and not everyone is waiting for Rock Band.