They had a problem. Their conductor, Mr. Harrison, had printed the digital scores in a rush, and a technical glitch had cut off the bottom three measures of every page.
For vector (born-digital) PDFs that look fuzzy: ensure your PDF viewer isn’t downsampling. In Adobe Reader → Preferences → Page Display → Use “High Quality” rendering.
Finding a "fix" for the Suzuki String Quartets for Beginning Ensembles, Volume 2