How can I turn off a Mac's display without sleeping the Mac itself? [duplicate]

Possible Duplicate:
Is it possible to put the display to sleep without putting the whole computer to sleep?

I have an iMac, and sometimes I want to play some music over night, without the bright display. The display will be turned off automatically several minutes later, but I would like a button that turns the display off instantly and keeps the music playing.

How can I do this?

Solution 1:

Ctrl+Shift+Eject will turn off the displays but leave the computer active.

Control ⌃+Shift ⇧+Power ⌽ for some Macbook

Solution 2:

Use ctrl + shift + Eject to turn off display.

You can also set a "hot-corner" to turn off display in a few seconds.