A Family Guy episode in May (the 150th, incidentally) included a few musical numbers, and a spoof or two. As Brian put it, "One thing we like to do at Family Guy is make fun of pop culture, by twisting it and mocking it and commenting on it." As Stewie added, "Yeah, and some times we just steal stuff and put our characters in it."
Then came a replica of Peter Griffin mimicking the jazzy pantomime of Jerry Lewis in The Errand Boy, set to Count Basie.
Here's a side-by-side comparison that shows Stewie definitely had a point.