Logic Masters Deutschland e.V.

A puzzle made for ThePedallingPianist's birthday! Of course it’s a day early but I think he will understand :). Big thanks to Marty Sears for aesthetic assistance. This puzzle relies on a bit of music theory knowledge but is perfectly possible with just the information from a primer I wrote for my first music puzzle. If you already have a good understanding of the major scale and chord structures within it this might be a bit below 5* (but still hard!). I’ve also made a logically equivalent puzzle with less busy aesthetics which you can play here. RULES:

Normal Sudoku rules apply. Text outside the grid is for note-taking purposes only.

Place 9 sharps and 9 flats in grid cells such that, for each type, there is one in each row, column, and box. Each digit 1-9 must be marked by exactly one sharp and one flat. No cell may have both a sharp and a flat.

Major Chords: The digits 1-9 represent ascending sequential notes in a major key (I will assume C major in examples but this is not required), starting with the root (e.g. 1=C, 2=D, 3=E, …, 7=B, 8=C, 9=D). Cells with a sharp are one half-step higher and cells with a flat are one half-step lower. Each set of three connected circles contain notes that form a major chord. The order, octave, and enharmonic spelling are irrelevant for this restriction. For example, the following are all C major chords: (1,3,5), (3,7#,5), (5,4♭,8). No two clues contain the same major chord (all of the previous examples count as the same chord for this purpose).