11 April 2023 Update

Added 9 new puzzles.  Experimenting with including some harmony notes in addition to the melody in Kiseki Knot. This might lead to some more interesting flipped-pitch puzzles in the future where the chord progression forms a plausible melody by itself.

Improved selection of the midpoint pitch.  This used to be a straight median which gave poor results in the melody+harmony case where there are low and high notes, but a gap in between (or when there are many high notes but less variation in the low notes).  The new algorithm takes an average after culling outliers.

Added 'Memory' challenge mode.  This prevents playback of the complete song.  You can either reconstruct it from memory, or use the link to the MV to try and match my simplified rendition with the original.

Added instrument selection.  There's now four choices of ok-sounding instruments that can be used to play the songs.  (Thanks to Gordon Reid's columns on https://www.soundonsound.com/ for some insights on bell frequency spectra.)

Minor UI improvements.  Radio button and checkbox labels are now clickable.  All the HTML files are now generated from discrete sources to better maintain different versions.

Fixed a bug where previously solved puzzles appeared as unsolved in the "By Name" dropdown menu.