Khatia Buniatishvili - Rhapsody in Blue

In 'classical' music, technical perfection is a given. If you cannot play (sing) ALL the right notes at the right time in the correct manner, you will not make it into a professional orchestra. Or you will be sacked if you are already in one. Those people work under tremendous stress, and some develop permanent damage. When you look at them during a performance, many of them look kind of bored. That is an illusion - what you are really looking at is somebody intensely concentrating every moment in time, even when they are NOT playing. (Of course, in ALL other genres of music, the concept of a 'mistake' does not exist.)

The way they get there is through extremely hard work. By the time someone first joins a professional orchestra, at say 22, 23 years old, he will already have spent about 12 years of 6 to 8 hours per day learning his instrument.

The soloist will not really play a roll, there. Of course, the orchestra will listen to the soloist to coordinate, and every member will do his very best with his part during the entire performance, irrespective of the soloist.

During a performance, the conductor actually has very little to do - basically all he does is to start things off and to determine the tempo.

His work is actually done before the performance. For something like the "Rhapsody in Blue", the orchestra would probably have had about two rehearsals without the soloist, and one rehearsal with the soloist.

The conductor is primarily responsible for interpretation. It is during the rehearsals that this is being sorted out - during the actual performance this is being replayed. During rehearsals, the conductor will frequently stop the orchestra and tell them how he expects that part/phrase to be played. The players will make notes on their scores accordingly. 

That is why you will see the conductor sometimes looking at particular parts/players of the orchestra during a performance and make some gestures - he is basically saying: Remember what we have discussed here? Please do it that way.

Some conductors like dancing and jumping around, others don't. It doesn't really make any difference.

Here is Leonard Bernstein in rehearsal with the BBC symphony, being an arsehole: