This is the theme to the underground levels in the very first mario game (im sure we all remember it quite well!)took a while to figure this out... its a bit rough at the end due to some fast playing and weird timing.

G---17--14--15--------17--14--15--------5---7---8--------5---7---8
D-----------------------------------------------------------------
A-15--12--13--------15--12--13--------8---5---6--------8---5---6--
E-----------------------------------------------------------------

G---------------------------------3-2-1-------------
D----------------------------3-4-2-------1----------
A-6-5-4---3--6--5--------4--3---------------2-1-0---
E------------------4--3---------------------------4-

Just Repeat that untill your fingers start bleeding, hurting, having spasms, etc.
good day to you all