Every Major Scale is constructed the same way. For this reason... any Major Scale will sound the same as any other Major Scale. The only difference will be the "Key" (of pitch).
The Major Scale is constructed:
The Greeks decided long ago that there would be a 'natural half-step' between the notes 'E' - 'F' and between the notes 'B' - 'C' --- This resulted in the 'C' Major Scale being the only major Scale that did not require accidentals (#'s or b's).
The 'G' Major Scale requires an 'F#' to complete its construction:
This is the only reason for the 'F#' (in the 'G' Major Scale) -- it is not mystical... it is music fact.
The Formula for any Major Scale is:
By Formula - if the root is 'C' -- the rest of the scale is:
By Formula - if the root is 'G' -- the rest of the scale is:
By Formula - if the root is (again) 'G' -- and the 'F' is not sharped - the rest of the scale is:
This is the Formula for Mixolydian (1,2,3,4,5,6,b7 -- or -- Major Scale (b7). Notice that the construction of whole-steps and half-steps have changed -- even though, only the notes of the 'C' Major Scale are being used. Changing the 'Root' (the 'Tonic') of a given Major Scale (while using only the tones of that major scale) - changes the ear's perception of that Major Scale. This changes the sound... because it displaces the relationship of the half-steps - as they are 'sounded' with (or against) that Tonic.