Photography - cannon low light lens

[johnnyzoooom]

I have a Cannon EOS 450D camera and would like to use it to photograph gigs (mainy small venue local bands) however i would like to upgrade my lens to a low light (fast) lens. I have between �300 - �400 to spend, but could go up to �500 at a push - can anyone recommend a good lens for the job?

[ACtheTROLL]

question doesn't mean anything

very broadly speaking - the focal length of a lens will govern the amount of light it lets in (f stop)
telephoto lenses generally let less light in depending onthe focal length - a 200mm lens will let more light in than a 500mm lens
generally the more you spend the wider the aperture

but as important is the iso rating - an iso 1600 is more sensitive to light than 200 - but will be grainier

in this case it depends how far away you are going to stand

a 500 mm lens capable of decent low light performance will cost a fortune

a standard lens with a much lower f stop won't cost half as much