Keyboard shortcut for Rotate?

In a painter tutorial video by Ryan Church he make mention of a keyboard shortcut 'Alt' + 'Space' which allows you to freely rotate the canvas on screen without having to enter an 'arbitary' amount.

I'm using a PC + XP Pro and when I press these keys the computer takes me to the 'file menu'.

Anyone know what the keyboard shortcut should be?

If I go to the 'customize shortcut' key I can still only get the arbitary window to come up at best, but I want to be able to drag and rotate the canvas freely as Ryan is doing.

cheers in advance

update: Found the answer!

I have to hold down the space key BEFORE additionally pressing the ALT key, I can then freely rotate the canvas. To restore to normal position, press space plus the additional ALT and tap the pen on the Wacom tablet.