/usr/share/doc/libsyntax-highlight-engine-kate-perl/examples/samples/highlight.abc is in libsyntax-highlight-engine-kate-perl 0.12+dfsg-1ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 | % Taken from http://www.gre.ac.uk/~c.walshaw/abc/#examples
T:Paddy O'Rafferty
C:Trad.
M:6/8
K:D
dff cee|def gfe|dff cee|dfe dBA|dff cee|def gfe|faf gfe|1 dfe dBA:|2 dfe dcB||
~A3 B3|gfe fdB|AFA B2c|dfe dcB|~A3 ~B3|efe efg|faf gfe|1 dfe dcB:|2 dfe dBA||
fAA eAA|def gfe|fAA eAA|dfe dBA|fAA eAA|def gfe|faf gfe|dfe dBA:|
|