[quote name='Grangur' timestamp='1396962151' post='2419126']
Doesn't all depend on if you read music or not?
If you're simply looking to find the root note and play from the heart n' soul using "the box" for the major scale, then I guess you don't need the keys.
What you would then need is the circle of 5ths to know where to go to when you want to go up/down a key.
[/quote]
Yes - worked for me. I only started learning them after I started using circle of fifths to learn major scales in all keys.
I'm in Disneyland right now and in the "be our guest" restaurant there is some sheet music. I was chuffed to spot the key signature straight away. If you see four flats you just count round the flats cycle till you get to the one with four. There's only 12 possibilities so it's not that hard to learn