The Conductor of the Orchestra Doesn't Play

Yesterday...I went to a concert. It was a real classic. I mean, it was a classical orchestra with violins, cellos...In fact there appeared to be four groups of instruments;

As it was late and I was tired, the instruments changed before my eyes and before I new it I was back to work. Wondering about this new solution we were working at. A question came to my mind;

What kind of problems do you