Sängers Morgenlied, by Franz Schubert
The benchmarking project for the LilyPond 2.1.x series, was the Ed. Peters version of a Schubert song. The result of 2.1.5 was nice, but certainly not perfect,
Here is the original,

and the result of LilyPond 2.1.35.
This is a page from a song-book, which is printed in a smaller format. Normal print uses 20 pt staff height, this uses 17 pt. In smaller print, staff lines should be relatively thicker. To match the thicker lines, the music symbols should also be relatively heavier. Both have been implemented in LilyPond 2.1. The difference is hard to see here, due to the limited resolution of computer screens. For a more detailed view, see the LilyPond PDF, available here.