In Chapter 15, you looked at some new keys—namely G, D, F and Bb major keys, together with their relative minors. As a result of this, we generalized some important principles. A major scale whose tonic (keynote) lies a perfect fifth above the keynote of C requires the addition of a sharp in the key signature (the key of G major). This gives the requisite whole-tone gap between the sixth and seventh degrees of the scale (TTSTTTS). Similarly, a major scale whose tonic lies a fifth above G (D major) requires two sharps.