The vast majority of blues, rock, and country music is played in cross harp, or second position (see What The Heck Is Cross Harp? ). This means that the draw 2 note on your harp is the "tonic" note. (or the key that a song would be played in)   Without my pitch pipe it is just trial and error. I pick up a couple of harps and draw on the 2 hole. When I find one that "sounds right", I play a little riff - draw 1, blow 2, draw 2 - I call it a "tuning riff". You can hear my Tuning Riff in key of G (cross harp on a C harmonica). If this riff sound right and fits, I have found the key. If it doesn't, I go back and grab another harp and try again.

The main reason for the pitch pipe is to prevent having to grab several harps to find a key -- all of the tonic notes are there in one place and labeled. I just blow around it until one fits, look at the key, grab the right harp for second position ( I have a position chart taped inside the lid of the pitch pipe case, if you need one you can get one here Kratt Pitch Pipes, and play my Tuning Riff . As long as that fits, I just jam away. If it doesn't, I go back to the pitch pipe and try again. The pitch pipe just makes the whole process faster. The particular brand to use doesn't matter, I use the Wm. Kratt "Master Key". I know Hohner makes a pitch pipe that looks like a harmonica that's more expensive than the Kratt, and I'm sure there are others. I just find the pitch pipe an easy to use crutch. I'm sure that more experienced players probably don't need this crutch, they probably learn to identify the key just by listening, but I'm not able to yet.

As to position, that is not relevant to the key -- key of C is still key of C whether played in first, second, third or twelfth position. The difference is that each position gives a different "flavor" to the sound of the harp. I guess only experience will allow you to pick up the position -- I still can't do it except for sometimes for third. If there is harp being played on the song you are playing with, you'll know second position isn't right if you're in the right key and you start playing along and it still doesn't sound right against the other harp (it will seem to be hitting notes you can't find).
You can order Kratt Pitch Pipes here.

Here is another perspective from from Uria at the  "Woodshed Music School, Buffalo, NY."

I've been read the thread regarding discovering the key of a piece that is on tape, CD, etc., so you can jam with it, or whatever....Maybe my approach will work for some others.  The problem is one of analyzing the various possibilities; however, the complication to that analysis is its sheer scope. So, the first attack is to narrow that scope into a workable size.

HARP SIDE:

1. Don't think of randomly searching through the 3,000 odd harps you have in those 5 steamer trunks --

2. There are 6 major keys and two "flat" major keys that are prominent in blues and rock and other harp-type music. I suggest that narrowing the scope of the analysis of key begin here and that your discovery project concentrate on those 8 keys: A, C, D, E, F, G, Eb, Db.

In my experience, your probability of fast key discovery is increased tremendously with this simple first step.  There will always be exceptions - Ab, for example. But, we're talking about probability of fast success in the search through narrowing the scope of available possibilities. Eight concentration points is far more doable at first than 12, 24, 48 , or whatever...

MUSIC SIDE:

The blues harmonic structure dominates the blues/rock/jazz idioms today, generally. In my experience, the blues changes are found - in a more or less sophisticated fashion - 98% of th time. So, in your analysis, assume the harmonic structure is a fashion of blues. What does this do for you?  It means you can narrow the scope of the analysis to the first measure of the piece, rather than aimlessly wondering through the entire song hit-or-miss..  Vanilla blues progression: I, IV, I,I, IV,IV, I,I, V, IV, I, V7.

NOW, what do you listen for? Two things: bass line, and chord tones. The bass player ensures the integrity of the progression through the proper placement of chord tones, and the musical placement of non-chord tones. Again, we want to narrow our scope through the proper use of probabilities. Professionals are trained from early on to place chord tones on the strong beats of a measure of music, and non-chord tones on the weak beats. Beats one and three are strong; beats two and four are weak. The highest probabilities are that chord tones - particularly in blues/rock/pop, etc. - will be found on strong beats.  SO. listen for: bass line; strong beats; chord tones - scope is narrowing to a workable load.

NOW where do you listen? In the blues changes, regardless of sophistication of substitutions to the harmonies, the probability of the first measure being I, that is the root chord/key chord of the piece is so close to 100% that to consider other possibilities [at first, anyway] is a waste of time. Concentrate your efforts on the first full measure of the piece, generally detected by the start of the expected melody line either sung or played - you may have to listen a few times to detect the start of the 12 bar structure if there is an introductory lead-in, but that is a piece of cake to determine.

NOW, how do you listen? Get one of the much praised pitch-pipes. Learn how to use it [shouldn't take more that one minute of your time].

1. Listen to the bass line, first measure of the 12 bar, beats one and three.

2. Listen again to determine on which beat - one or three - the lowest bass note is played.

3. Commit that note to your musical memory.

4. Take the pitch-pipe and , going through the 8 keys list I mentioned above, match the memory-pitch to the pitch of the pipe.

5. When you get a match - and you will - that pitch is the key of the piece.

SUMMARY:

What? Bass line; chord tones; strong beats.

Where? Measure one.

How? Pitch pipe/prominent key search [A, C, D, E, F, G, Eb, Db]

Determine the beat one or three lowest pitch from the bass line.

Match that pitch to one of the pitch pipe 8.

RESULT:

High probability you got a match quickly and with little trouble.  Grab that harp and "be jammin'"  There are some additional things you can do on the turnaround measures to analyze more complicated forms and stuff. I hope, however, this will provide a structure for narrowing your analysis and finding keys easily and quickly.

Uria....

Here are a few albums that I have found the song keys by using my Kratt Pitch Pipe. If I can figure out the position I'll note it, if not I'll just leave it blank  If the entry is blank that means I'm still working on it.  If you have any specific requests, Send Mail to John Watts and I'll try to post it here as I have time if I have access to the album or song.  If you think there are any mistakes here please let me know. If you click on the song title you can go to the Spree.com site where they have RealAudio clips of some of the tracks.

Blues Masters Vol. 4: Harmonica Classics by Various Artists

Cut #	Song Name	Song Key	Harp	Position	Comment
1	Juke	E	A	2nd
2	Ends & Odds	E	A	2nd
3	Rocket 88	E	A	2nd
4	Help Me	F	Bb	2nd
5	Messin' With The Kid	C	F	2nd
6	Blues With a Feeling	G	C	2nd
7	Sugar Coated Love	E	A	2nd
8	Steady	F	Bb	2nd
9	I'll Be Around	G	C	2nd
10	I Was Fooled	Ab	Db	2nd
11	Take a Little Walk With Me	E	A	2nd
12	Easy	F	Bb	2nd
13	Boogie Twist	C	F	2nd
14	Wolf Call Boogie	E	A	2nd
15	Last Night	A	G	3rd
16	I Got Love If You Want It	F	Bb	2nd
17	Cherry Pink & Apple Blossom White	A	A	1st
18	Christo Redemptor	C	Bb	3rd

Blues Masters Vol. 16: More Harmonica Classics

Cut #	Song Name	Song Key	Harp	Position	Comment
1	Off The Wall	G	C	2nd
2	Odds & Ends	E	A	2nd
3	Cotton Crop Blues	C	F	2nd
4	Keep It To Yourself	A	D	2nd
5	Help Me	A	D	2nd
6	Born In Chicago	A	D	2nd
7	I Hear You Knocking	E	A	2nd
8	Jump The Boogie	D	G	2nd
9	Come Back Baby	F	Bb	2nd
10	Pawnshop Bound	G	C	2nd
11	Baby Scratch My Back	F	Bb	2nd
12	The Briar Patch	D	C	3rd	chromatic
13	All Night Boogie	G	C	2nd
14	Shake The Boogie	G	C	2nd
15	Whammer Jammer	E	A	2nd
16	Hootin' Blues No. 2	E	A	2nd

Track Number	Key
1	E
2	A
3	C
4	F
5	D
6	G
7	A
8	F
9	E
10	A
11	C
12	E
13	G
14	D
15	A