Here's an interesting blog post I found about Led Zeppelin's song "Black Dog" by Paul Carpenter from Superset. I especially liked the bit about the time signatures:
The main riff of the song came from John Paul Jones. He wanted to write an electric blues that was too tricksy and complicated for people to dance to automatically. The band tried various embellishments of the original 5/4 signature – a 3/16 version was mooted but was ruled out because of the difficulties of playing it live. In fact, the band would often play the song in straight 4/4 time live just to keep it simple.
Read the full article here: http://www.itsafamilything.co.uk/black-dog-led-zeppelin