1. In 1877, Thomas Edison demonstrated the first phonograph to the public at the Menlo Park Laboratory in New Jersey. Although not in Massachusetts, the invention of the phonograph revolutionized the music industry and paved the way for modern-day recording technology.

2. On December 6, 1892, the Boston Symphony Orchestra performed its first concert at Symphony Hall. The hall, renowned for its acoustics, has been the home of the BSO ever since.

3. In 1970, Roxbury Community College was established in Boston. The community college has since served as a hub for education and workforce development for Boston's communities of color.

4. On December 6, 1989, an armed man entered the École Polytechnique in Montreal and opened fire, killing 14 women and injuring 10 others. This tragedy, known as the Montreal Massacre, sparked conversations about violence against women and encouraged activism in support of gender equality.

5. On December 6, 2006, the Massachusetts Supreme Judicial Court ruled that same-sex couples were entitled to marry under the state constitution. Massachusetts became the first state in the nation to recognize same-sex marriage, paving the way for nationwide marriage equality.