"In-A-Gadda-Da-Vida" by Iron Butterfly....
Or, to give it it's true original title..."In The Garden Of Eden".
The story goes that their guitarist - who came up with the title - was off his face on some substance or other, when his bandmates arrived at the recording studio one day.
He TRIED to tell them he wanted to call the forthcoming release "In The Garden Of Eden", but in his slurring physical state, it came out as "In A Gadda Da Vida" and they decided to stick with it.

Be not afeared. This band is full of noises, sound and sweet airs that give delight and hurt not.
- William Shakespeare