Personally, sometimes I can’t work without some music in the background. According to this snippet from NPR’s Intersections, Art Spiegelman also needed a little sound to inspire him while creating Maus. Along with the recordings of his father Vladek, Spiegelman also tuned in to the Comedy Harmonics (read the article), both of which you can listen to on the site. I had some trouble playing the recordings directly beneath the article, but the ones at the top of the page are interesting when you put them into context. The clip from Vladek is transposed almost verbatim into the comic, which I felt really made it pop in terms of authenticity.
If you look around the sight (i.e. just below the article and somewhere to the right) there are also some links (some broken) to articles about Maus from NPR and other sites.