This song was Stevie Nicks's third solo single, from her first solo album. It just narrowly missed being a top 10 hit - peaking at #11 - but endures to this day. The song was written as a reaction to the deaths of Nicks's uncle and also John Lennon - the "white winged dove" was representative of death, in this case.
But c'mon. We're here to talk about that guitar riff, right? It's a bunch of 16th notes strung together, and it unrelenting throughout the song. Those familiar with The Police know that the riff is remarkably similar to one featured in one of their songs, "Bring On The Night", but it wasn't a straight lifting and was done with complete authorization - as Andy Summers and Stevie Nicks had discussed it in 1981.