Tuning tuna

Topic: you can tune a piano, but you can’t tune a fish.
A piano is tuned by a human to make it sound better, so why can’t a cat tune a tuna, which would be easier since it is similar, as do all things that work together (such as cat and fat rat, or cat and mat,) to make it taste even more delicious? I’ve tried tweaking the can, putting it in my water, on the floor, or in the dog’s food, but it either doesn’t work, gets wet, gets you yelled at, or eaten by the dog. Why is it so hard to get fresher tuna?