Newer stuff
http://www.youtube.com/watch?v=pcawnRIyeok
http://www.youtube.com/watch?v=ttOBnmXFDtQ
Older stuff
http://www.youtube.com/watch?v=RtmW2ek7WkQ
http://www.youtube.com/watch?v=IJ7l1Oxm40k
They started with a heavy blues influence and became more pop like with the Stevie Nicks era.