One of the best, if not the very best, pure love song in the Led Zeppelin catalog, 'Thank You,' which is No. 41 on our countdown of the Top 50 Led Zeppelin Songs, finishes off side one of their classic second album wonderfully.

The warm, inviting guitar riff provides the platform for the simple, yet effective, melody. Robert Plant's plaintive and sincere lyrics melt with the music to give you that warm all over feeling. The "little drops of rain" section in the bridge tags on some old fashioned backing vocals from Jimmy Page that add the perfect touch here.

The mix of acoustic and electric 12-string guitars are Page's weapons of choice, and the solo, though without the fanfare of his electric work, is one of his best. John Paul Jones' haunting keyboards and John Bonham's understated drumming are the other pieces that make the puzzle whole. The band are all working for the good of the song, something that despite the tendency towards bombast in a live setting, never escaped Zeppelin in the studio. The song always takes precedent over any musical prowess.

In 1994, Page & Plant gave new life to 'Thank You' as part of their 'Unledded' project, and in 2012, the song sounds as beautiful and moving as it did in 1969. Simply stated, this is, perhaps, Led Zeppelin at their purest and most vulnerable.