Why do you think the A harmonica is most used in the blues?
That's what David says and I believe him and yet...
I've been zipping through all the lectures here playing along with my baritone uke and guitar when I can't keep up with the harmonica stuff (yet) to get an overview, which has been a great education on the blues for any instrument I think. I've found some important beginner ideas and instructions for the harmonica for myself pretty far along in the lessons so I'm really glad I'm doing it.
Blues in the key of E though makes me use the B chord as the fifth though which is a killer on the uke and guitar. No problem on my fiddle, but no key is a real problem on the fiddle. I heard a sax player say that a lot is in the key of E because the guitar can be played in an open way since the guitar already is in the key of E with those two E strings, but the killer B chord kind of ruins that hypothesis does't it?
The very first blues progression we learned in my guitar class was the key of A because A, D and E are all very easy open chords on the guitar. The key of G also has all simple chords, G, C and D and does the key of D wit D, G and A.
I just don't get why E would be the most popular! 3 sharps versus just one or two for the G or D scales also seems so more complicated for other instruments.
Why do you think E is the most common key for the blues?
Barre chords are not the only option for playing a B chord. I'm not much of a guitarist, but if you listen to old-time blues guitarists paying in E (when they use standard tuning, which is not a given), you won't hear a lot of barre chords. (Barre is the correct spelling, by the way.)
In much early blues playing, the chord changes are only implied and not actually played.
Double stops are not the only reason that amateur fiddlers like open-string keys. They're also the keys that are most easily played in first position. Flat keys not only take away open strings as tonic and dominant notes in the scale, they also require half-position fingering. I spent several years as the harmonica playing member of a fiddle club, and got to hear ther complaints when a tune in F or Bb would come up.
I still disagree that almost everything is in E. It simply isn't.
The keys of E, A, D, G, C, and F are all commonly used in blues.
Here's a sampling of well-known blues songs involving harmonica in all six keys, with Youtube links:
===Key of E
Little Walter Jacobs, The Toddlehttps://www.youtube.com/watch?v=Im2bVA0ArNI
Little Walter Jacobs, Jukehttps://www.youtube.com/watch?v=3J3eGUATzaY
Little Walter Jacobs, Roller Coasterhttps://www.youtube.com/watch?v=6eXu8GenNys
Junior Wells, Cha Cha in Bluehttps://www.youtube.com/watch?v=QBYdmAgq-e8
Muddy Waters (with James Cotton), Got My Mojo Workinghttps://www.youtube.com/watch?v=8hEYwk0bypY
===Key of A
Sonny Boy Williamson II, Trying to Get Back on my Feet https://www.youtube.com/watch?v=Kujts3TemvM
Little Walter Jacobs, Mellow Down Easyhttps://www.youtube.com/watch?v=q3W1kkG0S5c
Little Walter Jacobs, Blues with a Feelinghttps://www.youtube.com/watch?v=UqUfuW6kZnY
Little Walter Jacobs, Just Your Foolhttps://www.youtube.com/watch?v=EITZ2CmJam8
Howlin’ Wolf, Cause of it all (first position)https://www.youtube.com/watch?v=QZS-Z7eSC9A
===Key of D
Sonny Boy Williamson II, Your Funeral and My Trialhttps://www.youtube.com/watch?v=wL8FgqihKNU
Little Walter Jacobs, Teenage Beathttps://www.youtube.com/watch?v=lIPdpcHeuSg
Little Walter Jacobs, Blue Lightshttps://www.youtube.com/watch?v=at8ZTtpCG8Q
Howlin’ Wolf, Smokestack Lightning (1964 live)https://www.youtube.com/watch?v=HTDjD_UdJYs
Muddy Waters (with Little Water), I Just Want to Make Love To Youhttps://www.youtube.com/watch?v=RnlvHP1AXPo
===Key of G
Sonny Boy Williamson II, Mighty Long Timehttps://www.youtube.com/watch?v=
Little Walter Jacobs, Hate to See You Gohttps://www.youtube.com/watch?v=dAWCr13Ri0s
Little Walter Jacobs, Off the Wallhttps://www.youtube.com/watch?v=0bnBhBkFq8I
Sonny Boy Williamson I, Shake Your Boogiehttps://www.youtube.com/watch?v=yq5RspThWwA
Baby Face Leroy Foster (with little Walter) Rollin’ & Timblin'https://www.youtube.com/watch?v=Pca_S6sj_SE
===Key of C
Sonny Boy Williamson II, Nine Below Zerohttps://www.youtube.com/watch?v=HmgBQmB9bNc
Sonny Boy Williamson II, Pontiac Blueshttps://www.youtube.com/watch?v=qtsYc6DPNMw
Sonny Boy Williamson I, Sloppy Drunkhttps://www.youtube.com/watch?v=9IAw47eexK8
Junior Wells, Checkin’ on my Babyhttps://www.youtube.com/watch?v=kYwOcWyhxH4
James Cotton, Soul Survivor (first position)https://www.youtube.com/watch?v=hAyNJAg3nPk
===Key of F
Sonny Boy Williamson II, Help Mehttps://www.youtube.com/watch?v=QPeP3M-NqFo
Little Walter Jacobs, My Babehttps://www.youtube.com/watch?v=duRp_avXtMM
Little Walter Jacobs, Quarter to Twelvehttps://www.youtube.com/watch?v=jwB03WKv1d4
Sonny Boy Williamson I, She Don’t Love Me That Wayhttps://www.youtube.com/watch?v=k3rMN0hSXD8
Muddy Waters (with Little Water), Long Distance Callhttps://www.youtube.com/watch?v=3ihX1vbs014
See the list I added in the above post - plenty of examples of harmonica blues in all they keys I mentioned.
Your expression of curiosity about implied chord changes got me doing some investigating, and I came up with a list of songs recorded two ways, with both with implied changes and actual changes.
In 12-bar blues, the most frequently implied but not played chord seems to be the IV chord in measures 5 and 6. One famous example comes from jazz, with Miles Davis' composition All Blues, from the Kind of Blue album.
Many musicians assume the IV chord is there and play it (and even the book of transcriptions makes the mistake of calling it a C7 (IV) chord despite the sonic evidence), yet if you listen to the recording, you hear that the bass riff does not change, staying on the I chord, while the piano chord goes from major to minor an the scale goes from Mixolydian to Dorian:https://www.youtube.com/watch?v=-488UORrfJ0
In the blues realm proper, there are many examples. Here's Muddy Waters doing I Can't Be Satisfied in 1948 with the implied IV chord, followed by the Rolling Stones explicity playing the chord:
Muddy Waters (1948) - No IV chord in the 5th and 6th barshttps://youtu.be/vTgwDknZlkA
Rolling Stones (1965) - with IV chordhttps://youtu.be/B0k10f8fPMw
While Muddy and bassist Big Crawford are consistent in that rendition, there are other songs where the IV chord appears inconsistently. For instance, this 1951 recording of Country Boy, with Muddy and LIttle Walter, where the IV chord disappears during the instrumental break and the following vocal verse, but is present during the rest of the song:
Muddy Waters w/Little Walter (1951)https://youtu.be/DN8QS4gk7AQ
Then there are the 12-bar blues that neither use nor imply chord changes, such as Howlin' Wolf's rendition of I Asked for Water (1956):https://www.youtube.com/watch?v=dUA9FUTieKA
Anther is Rolling and Tumbling, as in the Baby Face Leroy Foster version I cited in an earlier post. In that rendition, chord changes seem implied but don't occur - and this is for once a reversal of the usual no-chord-to-chords transition over time: In the earlierst known version, by Hambone Willie Newbern in 1929, the IV chord occurs both in the first two measures and in the fifth and sixth, while the V and IV chord in the turnaround are as much implied as played:https://www.youtube.com/watch?v=OlARZkfGDOE
One of the most striking examples of implied chord changes is this 1930 rendition of Come On Over To My House by Geeshie Wiley and Elvie Thomas, played over a single guitar chord:https://www.youtube.com/watch?v=lQt83Qs1X3k
Here's Oscar “Buddy” Woods playign the same song in 1937, with full chord changes:https://youtu.be/3hKCIx44mso
A widely used song form uses what I call Saints changes - the same form and basic chord changes that have been in use for When the Saints Go Marching in since its first recording in 1923 by the Paramount Jubilee Singers:https://www.youtube.com/watch?v=hpuFgqlDP4c
The earlist occurence of this song form that I know of is Swing Low Sweet Chariot, composed around 1860, and popularized during the 1880s by the Fisk Jubilee Singers, who recorded it in 1909, moving off the I chord only for the final V-I cadence:https://www.youtube.com/watch?v=GUvBGZnL9rE
Here's Etta James doing the same song sometime after 1960, with full gospel treatment and plenty of harmonic movement:https://www.youtube.com/watch?v=Thz1zDAytzU
Another song in that form, This Train, provided the melody and form for one of Little Walter's biggest hits, My Babe, penned by Willie Dixon. Here's the earliest known recording of This Train, by the Florida Normal and industrial Quartet in 1922, with no chord changes:https://www.youtube.com/watch?v=d7zLFDTvrlU
Here's Little Walter doing My Babe in 1955:https://www.youtube.com/watch?v=duRp_avXtMM
Still another song in Saints form is Nobody's Fault But Mine, which originally had no chord changes, but later did. Here's Blind Wilie Johnson playing it in 1927:https://www.youtube.com/watch?v=Y_o4omd8T5c
And Paul Butterfield’s Better Days adding chord changes in 1973:https://www.youtube.com/watch?v=cQbiEi4AwAY
Finally, here's an 8-bar blues, You Got To Move, with Mississippi Fred McDowell in 1964 and no chord changes:https://youtu.be/mtlVSedpIRU
The Rolling Stone recorded it and kept the lack of chord changes in 1971, but when Aerosmith recorded it in 2004, they added the implied changes:https://youtu.be/y6sos0NJRUA
I'm not at all sure that the A harp is the most common in blues, though it certainly is popular.
Why blues in E?
The low-pitched open strings on the guitar give strong bass notes and open chords in first position (guitar hand positions, not harmonica key positions). The lowest, of course, is E, followed by A, D, and G, all popular keys for that reason. Violin open strings are the same notes in the opposite order: G D A E, and you find that those are the most popular keys for fiddle tunes.