Final answer:
Brenda used a language called Squeak to program music and wrote systems programming every week using computer science fundamentals.
Step-by-step explanation:
Brenda programmed music using Squeak and focused on systems programming with Modula-3, demonstrating practical application of computer science in creative fields.
Therefore, the missing words in the question are: Squeak and systems programming. Squeak is an open-source programming language, part of the Smalltalk family, known for its multimedia capabilities and thus, enabling the programming of music.
On the other hand, systems programming with Modula-3 involves using a language designed for systems programming with robustness, safety, and concurrency features.
Brenda's activities are indicative of a real-world application of computer science concepts taught at the high school level, connecting the principles of coding and software development with creative processes like music composition.