As a public school music teacher (of 15 years) I have observed students with high levels of aptitude who applied themselves and achieved greatness. However, I have also had high aptitude students who did not apply themselves and were surpassed by students will lower potential but higher work ethic.
I often wonder, is aptitude or potential a set figure, or can it be increased. Theoretically, potential is a set figure that represents the maximum level of achievement one can reach. I am not convinced that the human brain/body is limited by set levels of potential, however. Neural scientists use to think that the human brain was incapable of cell growth after a certain age. One medical study using tracer dye to research cancer cell growth inadvertently revealed new brain cell growth in senior citizens. This has led to other studies in the field of neural plasticity with convincing results. If the brain is capable of new growth, then it is impossible to place limits on a person's potential for achievement.
Why bring all this up? We do not have the ability to change the genetics that we have inherited. We do, however, have the ability to make the most of (or even raise the ceiling of) the abilities we were born with. As a young musician, I was limited in the areas of reading, dexterity and stage presence. Through hard work I have been able to elevate my achievement in all of these areas. I cannot prove whether I have raised my potential or just reached a higher level of my existing potential, but I have experience significant increase. This is what every musician should strive for. If you love music, and you desire to pursue it, then pursue it wholeheartedly. Strive for your maximum level of achievement, and then raise the bar even higher.