On a daily basis, I often ask my students to do more than one thing in a particular lesson. This is reasonable. I may ask a voice student to think about breathing or posture at the beginning of the
lesson, and later, talk about the intention of the character they are portraying. These are all reasonable things to ask. But it's not reasonable to ask a student to think about all of these things
at the same time, because of the forty watt bulb. Let me explain…
The limitations of the mind of the forty watt bulb is one of the reasons practice is important, and why we call it practice. As musicians, we practice individual components of our art, or practice everything all together at once, but it's nearly impossible to focus on more than one element (hand position, rhythm, pitch) at a time. Ideally, a single element is targeted, and practiced until it becomes routine. Once an element thoroughly accomplished, it's stored in long term memory. When an element is saved in long term memory, it can be performed without the use of the forty watt bulb, and combined with a newer, forty watt using component of music. Generally, an element that hasn't yet been mastered can't be combined successfully with another forty watt-using element without overwhelming and/or confusing the musician.
As a teacher, I find it's important to limit the expectations of both myself and the student to focusing on one forty watt element at a time. I teach both voice and piano, but I find that this is easier to accomplish with piano students. Pianists have external instruments they can see and hear. Singers have the more complicated task of using their bodies as their instrument, most of which they can't see or even hear accurately. Vocalists are also including language, intention, and character elements. It's very easy for a singing student to become overwhelmed and assume they aren't "doing it right" because they are trying to hold more than one forty watt task in their minds at once. None of us learn well while we are condemning ourselves. Condemning ourselves takes all forty watts which leaves nothing left over for learning or practice.
So, here in "Studiolab", I remind my students, and primarily myself as their teacher, to focus on one thing at a time and to practice the mindful awareness of the compassionate mind of the forty watt bulb.