How to change the settings on the iPhone 4 so that?

The backlight is permanately bright so it doesn't lessen brightness or goes on "dark" mode. I have it connected to my computer so it's charging and I want it to display lyrics on Soundhound so that I can follow allow while listening to music that I have on iTunes.

First turn off auto lock to never. Go to settings- general auto lock. Then for your brightness just go back to settings and choose brightness and slide to highest. I wish you can turn on and off the light sensor but apple did not think this out.