Behind all the dazzling tools and techniques developed in Lean, there is a common basis: the scientific method.
Sorrily, thanks to the entertainment industry, the word 'scientific' evokes the image of a pedantic teenager, with presumable difficulties to get laid, dressed in white coat and doing silly things with baking soda (on that regard, it's curious how many Hollywood productions equate "scientist" to "mad scientist").
But the scientific method, in fact, is the best tool we have for the exploration of reality. To move ahead through reality and reach objectives, we have to do trial and error anyway. That trial an error can be done haphazardly, or, if you want to maximize your results, in an orderly manner. That's what the scientific method provides.
The scientific method works through iterations. The most popular model to describe those iterations is the Shewhart cycle, popularly described as PDCA (Plan Do Check Act). I prefer Shewhart's original formulation as PDSA (Plan Do Study Adjust), although, in the end, it's just a matter of semantics; just go with the words that speak more to you. Here is a basic description of each stage:
Taken to the field of music, here is an example where I think I practiced these steps intuitively, many years before I knew what the PDSA cycle was. In my band in those times, when we rehearsed (Do), I used to record the sessions and later listened to them writing an index card for each song with arrangements and things to improve, lookouts (Study)... that way, in the next rehearsal, we could discuss quickly each song and its 'hot spots' (Plan) before start playing it (Do).
I cannot tell you how great the results were, in terms of both playing quality and also motivation: this kind of cyclical structure got everybody on the same page quickly, and we never had to start a rehearsal 'in cold', out of the blue anymore.