I’ve always admired jazz musicians. Classical musicians exist in a world of certainties, these are the notes and the order in which to play them, the articulations, the dynamics. Jazz has its structures (solo here, main theme again here) but there is space for creativity and improvisation. If you suggest doing a jazz solo to a classical musician you can see the beads of sweat run down their faces. They need the dots. I am the same, the only time I can ever do a mediocre solo in a moderately jazzy situation on the piano is with the help of a fair amount of alcohol to reduce my classical inhibitions. 

Harrison Ford
Harrison Ford in Indiana Jones and the Raiders of the Lost Ark© Lucasfilm

I have had ideas in rehearsal that seemed quite good and then in the middle of the actual concert realised that they were not very good ideas at all, that they worked in the cool of the rehearsal space, but not the heat of performance.  Sometimes you just have to...