Well then we just disagree. I think they are a pollution.

I'd say the voice, cause if you can't sing the blues with a bit of soul, you have no business singing them.

guitar, cause when you listen to some Blind Willie Johnson you know it is true.

Guitar, definitley. Twelve bar blues was made for it.

hmmmm... i think it's a tie between piano and guitar....that's a tuff question

Guitar because most of the great blues players were not piano players. Even buying a guitar was a major investment for them or their families let alone a piano. The piano really should not even be considered for this question.

After the guitar would come harp.

And finally, blues doesn't even need instruments let alone several instruments as Sammo claims. Someone singing to the beat of clapping is enough for the blues, which is were blues came from.

What blues piano players are you going to compare to

Robert Johnson
Son House
Blind Willie Johnson
Charley Patton
Lonnie Johnson
Blind Willie McTell
Blind Lemon Jefferson
Rev. Gary Davis
Brownie McGhee
Blind Boy Fuller
Blind Blake
Muddy Waters
B.B. King

the list goes on and on. There is a reason the guitar dominates blues!

I disagree. You can't play 12 bar by clapping. Old blues is stripped down yes, but even so instruments like the piano and guitar were used, often together. Old blues songs that only contain one instrument (I can think of plenty) don't actualy sound like blues songs. Some of them are very good, but the only think that makes them sound like blues songs is the singing or the lyrics. If they weren't by blues artists it would be difficult to categorize them as blues.

Guitar and harp are obviously the most important instruments, historically. And maybe the best also but I, for one, am not sure. What if they would have had as much access to the piano as to those 2 instruments?

Just wondering....

I like the harmonica. A good harmonica part can easily make the difference between a good and bad song.