so ive got this song right... its got a little chord progrssion that goes somthing like this C1 - C2 - D* - C1 - D* - C2. those are jsut what i named the chords anyway... heres what they look like:
e|-0-|                e|-0-|
 |-5-|                 |-3-|
 |-6-|                 |-2-|
 |-7-|                 |-4-|
 |-0-|                 |-0-|
E|-0-|      = C1      E|-0-|        =D*

E|-0-|      =C2

so yea... that little chord progression on an acoustic guitar with some electric reverd and a harmonica solo is gonna be bad ass. problem here is... i donno which harmonica to use... ive got all the keys... help...
try G. thats my fave, and if im not mistaken 2nd position in G is C (or maybe its the other way around).. i dont know much theory behind harps.. i just play em. ( i have 7 diff keys)
If above poster is right and it is in D major (A mixo), then you should use an A harmonica, second position (which is D)