Final answer:
A soloist is typically meant to be distinctly heard above the rest of the performing group. While frequency does affect perception of loudness, it is the composition and performance that ensure the soloist's prominence. The musical arrangement is determined by the intention to highlight the soloist's part.
Step-by-step explanation:
It is generally true that a soloist should be heard above a performing group. When a soloist is featured, it is usually the intention of the composer and the conductor to highlight the soloist's performance. Hence, the rest of the performing group will often play at a dynamic level that allows the soloist to stand out. This does not necessarily mean the soloist will be louder in terms of decibels; rather, the arrangement and orchestration are crafted to ensure the soloist can be clearly heard. This dynamic balance allows all the musical parts to be appreciated, while still giving prominence to the soloist's part.
It is a misconception to believe that higher frequency always corresponds to greater loudness or intensity; it is the context of the music that determines which part should be predominant. For example, in a concert setting, an instrument with a lower frequency might be less prominent if the soloist's part is written in a higher range. However, all notes and melodies are part of a cohesive whole designed to be heard by the audience simultaneously.
Therefore, while frequency can affect perception of loudness, the primary goal is to ensure the soloist's part is audibly distinctive when performing with a group.