* It uses valid HTML and JS. (You could also make it work without JS as a fallback and I love progressive enhancement, but it's not a requirement specifically for accessibility. Actually, JS can contribute a lot towards accessibility.
* The toggle button uses either `title`/`aria-label` or visual text in addition to the ≡ icon.
* The focus states are clearly visible for keyboard navigation.
* The correct ARIA attributes for the interactive elements are used.
* Depending on the menu, think about a focus trap/loop.
1. The drum beat is just the Rock 1 preset of the Suzuki Omnichord: https://www.youtube.com/watch?v=EDX6l9_58RA
2. Del tha Funkee Homosapien wrote the full lyrics in 30 minutes with the help of the book "How to Write a Hit Song": https://www.youtube.com/watch?v=Qq2qSq6NpNY#t=373
3. The first version of the song didn't feature Del, but the British group Phi Life Cypher: https://www.youtube.com/watch?v=ZM-DK3b5yuo