The harmonica is ready to play. It requires no accessories or tuning to be at it's best right out of the box. (The box is important . Always put the harp back in the box after playing and it will be your friend.)

This is one of the harmonica's most pleasing features. Stuck in traffic; blow a little blues. Need some coin; throw down a hat and get to work. Standing around the old trash-can fire with your unemployed pals; 0-60 on "I'm Going Down That Road Feeling Bad" in 2 seconds flat. The harmonica is the instrument of "The People". The cruel irony is that the majority of "The People" can't stand the noise that comes out for more than a few seconds unless it's in the hands of a competent operator. This, combined with the common belief that anyone can play it right away (cue up" Oh Susanna") has created a nearly unbearable tension between the harmonica, its enthusiasts and the rest of humanity. I believe that this tension can be relieved and that the harmonica can take its rightful honored place in the post- apocalyptic world to come.
First the instrument itself. There are many types of harmonicas to be had from the tiny (the Little Lady, 4 holes, an inch long) to the Chromatic (2 harmonicas combined to get all the notes) enormous (the bass harmonica a foot and a half long, beloved by master blogger,E. Danny Barnes).I choose the Marine Band 10 hole diatonic that has been the mainstay of blues and country musicians since 1896. There are many makers and popular styles of the 10 hole diatonic. To get an earful about any aspect of the harmonica universe, subscribe to Harp-L on the web.
Buy your first harmonica in the key of A. The Key of A harmonica is pitched in a comfortable part of the harmonica spectrum that runs from (low) G to (high) F. It's nice for the player and the listener.
Once you have your harp put in your left hand with the words "Marine Band" facing up and pucker up and blow. You don't have to blow very hard. Breathe from your diaphragm. There is much information on technique to be found on the web and in books. More than you'll ever need.
Intelligent practice is the way to gain skill. A little practice each day is better than hours one day then days of neglect. The real question is "What am I trying to do?"
Unless you are a stone cold genius savant the answer will be found in listeningggggggggggg.
Much listening. Your own genius will be unleashed by hearing great music. The harmonica is an instrument of emotional expression. The world will love you for having at least a touch of melodic lyricism. All good music has it; even the most hard core psychodelic fantasy freakout, a favorite of harmonica devotees.
All music is fair game for a dedicated player, any instrument or style. Most would like to hear some good harp playing. Here are some of my faves:
Sonny Terry, Little Walter Jacobs, Big Walter Horton, Red Parham, De Ford Bailey, Jimmy Reed,
Toots Thielmanns, Howard Levy, Paul Butterfield, Grant Dermody, Dr. Humphrey Bate, Gwen Foster, Carlos Del Junco, Charley McCoy,Sonny Boy Williamson 1&2, Stevie Wonder, Gary Primich, William McCoy, Doc Watson, Woody Guthrie, Peg Leg Sam, Madcat Ruth, Tom Ball,Joe Filisko and on and on.
My list is weighted toward the country and non-amplified end of the harmonica landscape. Once you find these guys you'll find dozens more of all sorts.
One last bit. Here's a poem by Robert Service.

The Song of the Mouth Organ
(with apologies to the singer of the "Song of the Banjo")

I'm a homely little bit of tin and bone:
I'm beloved by the Legion of the Lost;
I haven't got a " vox humana" tone,
And a dime or two will satisfy my cost.
I don't attempt your high-falutin' flights:
I am more or less uncertain on the key:
But I tell you, boys, there's lots and lots of nights
When you've taken mighty comfort out of me.

I weigh an ounce or two and I'm so small
You can pack me in the pocket of your vest;
And when at night so wearily you crawl
Into your bunk and stretch your limbs to rest,
You take me out and play me soft and low,
The simple songs that trouble your heart strings:
The tunes you used to fancy long ago,
Before you made a rotten mess of things.

Then a dreamy look will come into your eyes,
And you break off in the middle of a note;
And then, with the dreariest of sighs,
You drop me in the pocket of your coat.
But somehow I've bucked you up a bit;
And, as you turn around and face the wall,
You don't feel so spineless and unfit--
You're not so bad a fellow after all.

Do you recollect the bitter Arctic night;
Your camp beside the canyon on the trail;
Your tent a tiny square of orange light;
The moon above consumptive- like and pale;
Your supper cooked, your little stove aglow;
You tired,but snug and happy as a child?
Then 'twas "Turkey in the Straw" till your lips were nearly raw,
And you hurled your bold defiance at the Wild.

Do you recollect the flashing, lashing pain;
The gulf of humid blackness overhead:
The lightning making rapiers in the rain;
The cattle-horns like candles of the dead
You sitting on your bronco there alone'
In your slicker,saddle-sore and sick with cold?
Do you think the silent herd did not hear "The Mocking Bird",
Or relish "Silver Threads among the Gold".

Do you recollect the wild Magellan coast;
The head-winds and the icy, roaring seas;
The nights you thought that everything was lost;
The days you toiled in water to your knees;
The frozen ratlines shrieking in the gale;
The hissing steeps and gulfs of livid foam:
When you cheered your messmates nine with "Ben Bolt" and "Clementine
And "Dixieland" and "Seeing Nelly Home"?

Let the jammy banjo voice the Younger Son,
Who waits for his remittance to arrive;
I represent the grimy, gritty one,
Who sweats his bones to keep himself alive;
Who's up against the real thing from his birth;
Whose heritage is hard and bitter toil;
I voice the weary, smeary ones of earth,
The helots of the sea and of the soil.

I'm the Steinway of strange mischief and mischance;
I'm the Stradivarius of blank defeat;
In the down-world when the devil leads the dance,
I am simply and symbolically meet;
I'm the irrepressive spirit of mankind;
I'm the small boy playing knuckle down with Death;
At the end of all things known where God's rubbish heap is thrown,
I shrill impudent triumph at a breath.

I'm a humble little bit of tin and horn;
I'm a byword, I'm a plaything, I'm a jest;
The virtuoso looks on me with scorn;
But there's time that I am better than the best;
Ask the stoker and the sailor of the sea;
Ask the mucker and the hewer of the pine;
Ask the herder of the plain, ask the gleaner of the grain---
There's a lowly, loving kingdom--- and it's mine.

Robert Service

'nuff said

Mark Graham