What are the hardest notes to find on a guitar fretboard?
https://www.gitori.com/blog/articles/hardest-notes-on-the-guitar-fretboard
'Gitori's Find the Notes game challenges users to find a given note in a highlighted area of the fretboard. Over the last 3 years, the game has been played by over 10,000 people, and I've collected 275,179 different data points on note identification. Based on that data, I have a heatmap of the hardest notes to identify on the fretboard.'