Can you be playing, for example in the key of c mayor but using all the notes of the key or scale but in low and high tones you know...

or do i have to use only the notes for one scale or you can play the same notes of scale being higher or lower pitch?

also is it different to play in scale or key'? whats the difference??
first of all, there is no difference whatsoever between playing within the key and the scale, a scale is just the ascending progression of each individual tone of your key, from root note to the next octave (I think I might've made that sound a little too complicated)

and as for staying in key, well, that's where modal changes come into play, you can be playing in the key of C major/ionian but be accentuating the minor qualities of it (6th scale degree of the key of CMaj), which would turn it into A minor/Aeolian, also, if you use the right chord progressions you can change into other major keys, other minor keys, or just a different modes, which could probably lead you into different major or minor keys
Ibanez RG121
Ibanez GTA15R Amp
red Allegro nylon-strung acoustic of unkown model

Quote by Mechanix

We play guitar.... we're automatically on top of the world.

To start with, you don't 'have' to do anything. Music is what you make it.

But if you use the notes A, B, C, D, E, F, or G and no others, with a root note of C, you are playing in C major. Whether you're using more than one octave doesn't matter.

Wrong forum, btw, this one's for lyrics.