ANSWER
Guitar Hero has been made for to only be played by the people playing it. It isn't made for playing on it's own. It is impossible.
You can play Rock band with a guitar hero guitar, but you can't play Guitar Hero with a Rock Band guitar.
The same way you play with a GH3 guitar
Do you mean with the guitar hero controller? Guitar Hero 3 is a game itself, so due to the inability of any console to play multiple games at one time, none.
Guitar Hero World Tour is Guitar Hero 4.
Guitar Hero World Tour and Guitar Hero Metallica
No. How do you expect Guitar Hero to make any money off of download-able songs if people can just play their own?
No Guitar Hero Aerosmith is a standalone Game. You do not need the Orignal GH to play it
yup
Yes
no. guitar hero 2 is just a better version of guitar hero 1.
No. You have to have a guitar (Can be "Rockband" or "Guitar Hero" guitar or a drum set.)
Custom songs are songs that Guitar Hero player across the world cerate in the Guitar hero studio. They make their own tunes and let others play and listen. Any one who has a Guitar Hero game with the studio in it can do it.