This is the little guitar part you hear on Fallout 3 and New Vegas whenever The  
Mysterious Stranger appears in V.A.T.S., or when you use the Mysterious Magnum. 

E----------------- 
B----------------- 
G----------------- 
D-----------0----- 
A---------2---1--- 
E-0-3---0--------- 

E---- 
B-7-- 
G-8-- 
D-9-- 
A-10- 
E----