While ideally we like playing to be holistic, in reality, different skills happen at different rates for different musicians. Periodization is a way to avoid injury and burnout by placing emphasis on different skills at different points in the year. For beginners, the periodization might be less evident, as there are a few core skills that are worked on before periodization is very relevant.
Periodization is really just a sort of scheduled emphasis, we are of course always working on these subjects in tandem.
There is quite a lot of science behind periodization, which is primarily used in athletics. It is incredibly translatable (as is much of the athletic research for use in music), and arguably musicians wouldn’t sustain the same injury rate as football players if it were more widely accepted in the culture.
Our studio’s periodization schedule is located here