The C major scale consists of all white keys on the keyboard.
The two tetrachords for the C major scale are :
Notice that the two major scales are interlocking. The upper tetrachord of the major scale is the same as the lower tetrachord of the G major scale.
Likewise the G and D major scales also share one tatrachord, so do the D and A major scales, and so on, all around the Circle of Fifths.