Which of the following musicians is credited with contributions to both jazz and classical genres?

The choice of "All of the above" is correct because each of the musicians listed—Dave Brubeck, Keith Jarrett, and Chick Corea—has made significant contributions to both jazz and classical music.

Dave Brubeck was known for his innovative approach to jazz, particularly in his use of unusual time signatures. His work, such as the famous album "Time Out," blends jazz improvisation with elements of classical music, showcasing his classical training.

Keith Jarrett is recognized for his deep improvisational skills in jazz but also for his classical performances. His classical recordings, including interpretations of Bach and Beethoven, highlight his versatility as a musician who bridges the gap between jazz and classical traditions.

Chick Corea is celebrated for his fluid playing style and compositional skills that thrive in both jazz and classical domains. His work in jazz fusion, along with classical works and collaborations with orchestras, further emphasizes his dual influence.

By recognizing each of these musicians' contributions, it’s clear that they have each significantly influenced both genres, justifying the choice of "All of the above" as the correct answer.