Final answer:
Richard Schulze rebranded his store 'Sound of Music' to 'Best Buy' in 1983, marking a shift to a wider focus on consumer electronics.
Step-by-step explanation:
In 1983, Richard Schulze changed the name of his stereo store Sound of Music to Best Buy. This rebranding signified a key shift in the business model, pivoting from a specialty audio store to a broader electronics retailer. This change laid the foundation for Best Buy to become one of the leading consumer electronics retailers in the United States and internationally.