We all go through cycles of highs and lows. In any given day, for example, your entire physiological system goes through a cycle of circadian rhythms.
I also believe that this cycle translates to the bigger picture. I sometimes go through periods where I am less satisfied and more frustrated with my playing than usual. These periods, I have grown to understand, are perfectly natural and when in such a period I try to remain confident that the pendulum will eventually swing the other way.
Sometimes too when working on something new, I can sound pretty bad. I often tell my students that in order to sound good in performance, you cannot be afraid to sound bad in the practice room. I jokingly say that “in order to get better you can’t be afraid to sound like a pig for a while.”
By this I mean that new music and techniques take time and wood-shedding – sometimes the process can be a bit ugly and results can take a while to show themselves.
A favorite radio program that I listen to on National Public Radio is Ira Glass’s “This American Life.” A while back I stumbled onto this video; his commentary translates to this topic – “working through the suck.”