Led Zeppelin fans have George Harrison to thank for inspiring 'The Rain Song,' which is No. 37 on our list of the Top 50 Led Zeppelin Songs. The Beatles guitarist reportedly remarked to John Bonham that the problem with the heavy rock group was that they never recorded any ballads -- which prompted Jimmy Page to write the music for the track, even tweaking Harrison's nose by borrowing the first two chords from 'Something.'

The result is more than a simple ballad; 'The Rain Song' evolved into an epic 7 1/2-minute progressive rock suite that is undoubtedly one of the most adventurous songs in the Zeppelin canon, with Page employing unusual tunings and layering multiple guitars for a shimmering, orchestral effect that John Paul Jones' keyboard work perfectly underscores.

Robert Plant tops the track off with an exceptional vocal performance that he later told Rolling Stone was his favorite on any Led Zeppelin album.