As a "beginning intermediate" player learning jazz piano solos, I have come across the following dilemma. I find myself struggling with 16th-note runs with the right hand & accompanying chords with the left hand. If I try to play all of the notes perfectly, I lose the tempo. If I try to maintain the tempo, I invariably hit some wrong notes. I have tried to slow down the tempo in my practice. This certainly helps. However, as soon as I play the correct tempo, the mistakes return. The question is: Should I practice at the correct tempo & accept the inevitable mistakes or strive for zero mistakes at the expense of tempo? Thank you for your help.