Mutation is not a bad thing. A lot of the flavour of apples is in the skin. The skin changes, subtly changing the flavour. The yellow on the Royal Gala apple below (the shade of a leaf) is actually the colour of the Gala apple its red colour mutated from.
The Royal Gala slightly less sweet than a Gala, partly because of more acids in the skin, it is redder, and it has a tougher skin. As a result, its fruit has a denser texture and, at least for the first few days of picking, is more aromatic than a Gala, because of that tougher skin keeping those aromatic esters from evaporating as quickly. A new variety of this kind, called a sport, comes from a mutation in a bud. Another kind of mutation occurs in an individual cell, and is not carried genetically to new shoots or trees. In this case, it appears as a band of colour on the fruit, representing one mutated cell and all her daughter cells as the apple grew. You can see that effect in the apple on the right below.
These effects probably come to the Gala from the Red Delicious. The parentage of the Royal Gala is Ribston Pippin x Newtown Pippin = Cox Orange. Cox Orange x Red Delicious = Kidd’s Orange. Kidd’s Orange x Golden Delicious = Gala, which then mutated to Royal Gala. The tendency to mutate in both bud and fruit is a strong characteristic of Red Delicious, which is itself a red-coloured sport of Delicious. The sweetness and scent of a royal gala, that can fill a whole orchard and attract bears from miles around, is recognizably Delicious, as is the tough skin that really separates this apple from Gala, and which comes with the red mutation. As for the beautiful scent, it all evaporates within three days of picking, especially from small, weak, shaded apples in the heart of the tree, or apples hanging from downward-growing fruiting structures, where there was little of it at best and skins were thinnest due to the shade. At its worst, as in the apples above, this effect leaves the apple tasting like water and a bid of acid from the skin. What I find fascinating here is that the ability of the tree to mutate readily, and to create many opportunities for flavour in relation to climate, is perfectly matched by care given the tree. In other words, the ability of the tree to position itself in relation to climate is matched by the ability of humans to manipulate the climate within the tree. The current model of tree production, to manipulate apple DNA to match industrial packing and storage procedures, and to grow the resulting trees in short-lived hedges, replacing human care with carefully-timed water-borne nutrients, manipulated by heavy clipping of the top of the hedge, and discarding the tree with the fruiting structures become weak and shaded, is far less able to change with changing climate or changing cultures. Be happy with mutations. The tree makes them to catch our eye. Be caught.