There are a few reasons for this pay disparity. First, principal players generally have more experience and skill than rank-and-file players. They have typically held their positions for many years and have proven their ability to perform at a high level. Second, principal players often have additional responsibilities beyond simply playing their instruments. They may be required to lead rehearsals, teach students, or perform solos. Third, principal players are often more visible than rank-and-file players and may bring in more revenue for the orchestra through their star power.
The pay gap between principal players and rank-and-file players can be significant. In some cases, principal players can earn double or even triple the salary of a rank-and-file player. However, it is important to note that the vast majority of orchestral musicians are paid well, regardless of their position. Even the lowest-paid musicians in a major orchestra can earn a comfortable living.