Decide to use the default paragraph indent. A zero indent means that you really then want space between paragraphs. And that in turn means that you get extra spaces between a tune and any Change notification. So for now use the default indentation to signal a paragraph and see how that goes. Possibly the tunes should be generate such that there is no paragraph between the graphic and the change notification, but I'd have to work out how.

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\newpage
\section{List of tune first lines}

You know the feeling. Everyone has just launched into a well-loved tune.
You've heard it before, but don't remember the name. So here's a list of
tune first lines to help you figure out what it is in time to join in.

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\setlength\LTright{0pt}
\begin{longtable}{lr}