The thing that makes this so tough is some people have natural talent... they can learn something in a week that takes the average person a month or more to learn. You start stacking up those weeks and you can see why some players are so superior to others. The average person really does need to hit the ground running maybe practice longer and be more effective with his practice time. The venue is also another thing. IF you are an entertainer and put on a great show but maybe don't play the most challenging pieces... you could be in demand and make a living. If you want to be a music teacher well then that is another thing. Now a concert soloing trumpet player ... that does require a gift as well as drive. Maybe if you narrowed it down a bit.