You probably all know the usertool "show note names" which can be found in the .Automatic group and was delivered by Noteworthy self.
I have made an extension of this tool. It does not only show the note names in the current staff, but it shows all the sounding note names in all staves. An additional staff with rests and note names in the Lyrics is added at the end of the score where up to 8 sounding note names can be displayed.
I also added information about the fact that an instrument can sound lower or higher then the displayed notes (> when it sounds higher, < when it sounds lower). A trumpet in B flat will produce a Bb when a C is played. "< C" will be shown.
For composing reasons, I finally added for each chord if the notes in a chord are part of an octave or a fifth (upper case for the bottom octave/fifth, lower case for the upper octave/fifth). This information could be helpful when checking for unwanted parallel fifths and octaves, since these sometimes unwanted parallels can only appear when these intervals are present.
To undo: just delete the (last) staff with the chord information.
A few remarks:
* triplets are converted into non-triplet duration notations and may therefore be slightly out-of-sync - but that is automatically corrected in the following chords.
* if staves have different time signatures, bar lines don't always appear at the same time. A bar line is added in the new chord names staff whenever a bar is present in one or more "normal" staves.
* this tool doesn't take care of scores where measures are added in between (but skipped) to cope with different verse texts, because it ignores master and local repeats. For this kind of scores the tool will produce a useless chord name staff!
* this version of the tool treats drum staves as normal staves, which may also show useless and confusing information!