Which announcement is made by the United States Marine Band regarding high school competitors?

The United States Marine Band announces a concerto competition for high school competitors, which serves as a significant opportunity for young musicians to showcase their talents and gain recognition. A concerto competition typically allows participants to perform solo with orchestral accompaniment, thereby not only highlighting their individual skills but also fostering a deeper understanding of orchestral works. This kind of event encourages student musicians to aspire toward high performance standards and can lead to further educational and performance opportunities, both of which are essential in their musical development.

The other options may represent beneficial initiatives in music education but do not specifically match the type of event or opportunity that the Marine Band is known for, which is focused on competitive performance rather than festival organization, online courses, or partnerships with schools.