how do I release a piano key quicker and still stay in rhythm? When I play a quarter note followed by a half note, I do not release the quarter note quickly and that causes a delay in playing the next note. I hold the half note for 2 beats but holding the quarter too long creates a wrong rhythm. I know how to count rhythms but my fingers do not release the note to go along with my counting.
If the note(s) you have to play afterwards aren't that far away from the note(s) you just played, one possible way would be to switch fingers whilst still holding on to the key, also called finger substitution. In one piece I'm currently practicing, I have to do that to play comfortably, as I arrive with my thumb on a note but have to play legato (no pedal) to the next note that I only can get with my thumb again.
If you have to jump or if it is a faster piece, I sometimes just let go a bit earlier. Otherwise I'd try to hide it with the sustain-pedal.
Those are just the ways I handle this, however I don't know if there's a textbook solution for this problem.