Whistle and Strum

One of the truly revolutionary TV shows of the 1960s was The Smothers Brothers Show. Mason Williams was one of their comedy writers and an accomplished musician. (Williams wrote Classical Gas.) Williams wrote the Smothers Brothers theme song, which to me is still one of the best whistle and strum songs. Here's a video of Williams performing it in 2006 along with another of his songs.

Enjoy.