To add to the confusion..I've personally heard Loui' of the Lost Bayou Ramblers say that their band prefers playing with the "D" accordion. That was a while back. Loui is the fiddle player, the singer, and the lead man of the band. So I figure he has some say as to what he likes or not.
I also play fiddle (novice) and the only problem I have with the "D" standard tuning on the fiddle, is that when I play and/or drone on the two smallest strings A and E, it's very high and piercing. This might have been one of the reasons "down tuning" came to be?? Otherwise, it seems you can do on a fiddle in standard tuning "D" what ever the hell you want to, as long as you're playing alone or with a "D" accordion. When they break out that "C" accordion, I have to tune my fiddle down to be able to play along given the rudimentary playing method I know. I can drone though, and drone playing is the absolute preferred method, when it's applicable that is. I once heard an ole timer say that he would start the dance playing with the "C" accordion and switch to "D" accordion to pep things up a bit on the last half of the night. Personally, I started out with a "C" accordion going by what everybody told me. "Those got dam jam sessions all play in "C". I guess for the simple reason of keeping it consistent. But I'd pick the "D" accordion over the "C" if I had to keep one and give the other away. The brightness of the "D" makes me happy and when played in the first position in the key of "D" ,if the singing is done like it's supposed to be, it's hard to beat. Singing in the key of "A" not so good. I have a standard tuned "D" and a 15cent wet tuned "C" accordion that sounds exactly like Iry Lejeune's accordion. With one stopper pushed down, I can make it dry tuned if I want to. This combination of the two accordions keeps me happy and satisfied. As far as Bflat or any other key, I say F*** THAT! That's only for confusing the hell out of beginner accordion players, fancy conniving professional players, and making us want to go spend another $2000 to buy and odd key accordion that won't match up to any of the old recordings. Why bother? To me, b flat singing sounds dull and flaccid. LOL. I'd sure like to know which Louisiana accordion player or builder first introduced the B flat to Cajun music. Because I might want to kick him in da nuts a time or two. I'm with you on this one Nedro! Yeah, WHY "C"????

And Furthermore! I think that all jam sessions should feature the "C" accordion one week and then the "D" accordion the next. For the benefit of variety. Fiddlers would have all dam week to retune their fiddles, or they can just grab their other fiddle that stays tuned "Sandard". This would be announced by the first chair master accordion player. He would tell everyone which accordion to bring the next week. Or, if you ever go to a jam sessions bring the "C" and the "D" if you weren't at the previous one and didn't get the memo. I once witnessed a young player walk in to the Savoy Music Center jam session unannounced with a "D" accordion and he was given 1st chair. That dude smoked it! When I say he played every button on that accordion I mean it. He knew what he was doing. I didn't see one fiddle player complain. Some of them retuned, some of them didn't. But I was just starting out and didn't know exactly what to look for. All I knew was, I couldn't play along with this "D" accordion player because all I had was a "C" accordion.

PS. Iry Lejeune did a few recorded songs with a "D" accordion. Not many, but he did.

PSS. I heard that it was Walter Mouton that introduced the B flat accordion due to him getting older and his voice needed a break. Steve Riley made it popular and mystical because all kinds of accordion players were trying to parakeet his songs. And then somebody called "BULL S***". B flat not so popular anymore now is it?

PSSS. Some fiddle players love B flat over all else. They say it's the easiest accordion to play with???? Never was able to fiddle along with a B flat accordion so I couldn't experience it. That's probably because there's no B flat accordions allowed in my vicinity! By God!

As a matter of fact, here is that accordion player that walked in to the Savoy Music Center jam session way back then and played that "D" accordion. He was younger and wore a butt cut parted hair style back then. LOL, but that didn't matter much.

Well Ned. Looks like you got a whole lot of answer there. This was a really fascinating discussion for me to read. I have no music background and just know what buttons to mash to make a sound.

Pretty funny when someone asks me to play an E note for them on one of my boxes. I have to count it out and then am not quite sure.


John in Oregon

Hey John, I've been through "not being sure" when asked to play in a certain key on accordion. Unfortunately, Marc Savoy didn't lay that part out too clear on his instruction videos. Neither did any of the other "Lesson Giving Masters." Mostly it's learned trial and error and memorizing after you've played along with a guitar or fiddle player. Some accordion players don't have that luxury. Back to fiddlers having to retune their fiddles to match up to a "D" accordion at a jam session.
PERSONALLY, IT TAKE ME ROUGHLY 1 MINUTE 30 SECONDS TO RETUNE TO STANDARD USING A CLIP ON TUNER. Some fiddlers are faster and do it by ear. I ONLY HAVE TO DEAL WITH MY SMALL "FINE TUNE" ADJUST SCREWS. I DON'T EVEN HAVE TO TOUCH MY BIG TUNING PEGS TO GO BACK AND FORTH BETWEEN "STANDARD" "d" TUNING AND "DOWN TUNING" "c". It's actually not that hard and no fiddler should complain about having to do it. But remember, you don't want to argue too much with a fiddler. We accordion players need all the fiddle players we can get!

Gotta love this video!

I was told that C was selected by the German promoters of the accordion.

Their approach was simple; "Vee Vill play und you Vill Listen". I makes as much sense as all the other reasons I have heard, :) :)

I much prefer my D/A melodeon but it lacks the Cajun sound.

Of course great music is great music, no matter what key it is in.

Ok RPr..Let's all speculate shall we. No need for anything solid or backed by evidence. Just throw on the table whatever pops into the old brain eh? I'm real good at doing that!!
I submit that the Germans didn't promote any certain key of accordion. They just sent what ever the ignorant store owners ordered. "Just send me a standard tuned accordion" they might have said?? LOL. I farther submit that the early Cajun fiddlers played with their fiddles tuned standard which would go nicely with a "D" accordion if you were able to get your hands on a "D" accordion. The first accordions, from what I read, didn't match up well to the standard tuned Cajun fiddles at first because they were in keys other than "D". Maybe the first accordions were in "G"?? But at some point in time the fiddle and the accordion got in sinc!! I would venture to say that this happen because a "D" accordion was purchased at some point in our history and that accordion player sat down and played along with a fiddle that was tuned "Standard"....and they hit it off! Remember to keep in mind that the Cajun accordion players learned their songs from the fiddler's repertoire at first. They then evolved to adapt to whatever music was available with the invention of radio. Lots of old timey tunes that would have been played on the radio would have probably been done in the keys of "D", "A", and "E". As in our Appalacian mountain music. Maybe that's where the term "Standard Tuned Fiddle" came from. Tuned standard to play "D, A, or E music! By God it wasn't "C"!! It was "D"! Why did it change?
I lastly submit that accordion players started getting "C" accordions because some popular accordion player like Joseph Falcon, or Lawrence Walker, or "IRY Lejeune" made all those old borrowed hits on a "C" accordion, and everybody wanted to be able to do just like him. Steven Riley did the same got dam thing with the "Bflat" accordion. B flat accordion sales went up after he produced all of his "stolen" hits layed down on his first CD's. I say "stolen" because they were just old songs taken by Steven Riley and the gang and redone and presented as new to the ignorant masses. Even as far as doing some of them in B flat. If you don't believe me, be on the look out for my future posts. I will prove to all of you ,for example, that Iry Lejeune took Amede Ardoins work, which was all in "D" and redid it in a manner not so easily recognized when Iry recorded them himself. Iry changed the speed of Amede's music and the key of the accordion to hide the fact that he was borrowing Amede Ardoins work. Which consequently, Amede also borrowed it from someone else that came before him. Oh, it gets pretty twisty. All kinds of manipulation and intrigue I tell you what! Hell, Elvis did the same dam thing. Stole from the old black blues singers, and made millions from it. Not to mention having the title of "The King" bestowed upon him.

Just something to add to this interesting topic, it may be irrelevant but the standard key for a harmonica tends to be C. As with Cajun accordion any instructional CDs feature a C harmonica and those beginner sets you can buy come with an instrument in C.
A is a popular blues harmonica key but C is considered the all round starter key.

Apparently if you go to a Cajun style jam in France the preferred key of accodion is D.

Consider the choices in musical keys A,B,C,D,E,F,G. Which key is exactly mid range? "D"...with 3 keys before it and after it. So why not choose to manufacture midrange "D" accordions? Makes sense to me. Not to mention how they would fit like a glove together with standard tuned (G,D,A,E) fiddles.

Nedro and others, let me point out another reason that the D accordion
might have been right for the early cajun singers.

Cajun men were, in general, smaller
than their grandchildren and great grand children are now at a comparable age.

A cursory study of the anatomy and physiology of the larynx, vocal cords,
and would suggest that the resultant smaller structures in smaller men would
change the acoustic properties of the resonating chamber. A smaller
larynx would naturally create a higher pitch.

John, your scientific analysis holds water. Small fellows with high voices. Tours of the River Road plantations near New Orleans point out that the French Caucasians were quite small, possibly 6 or 7 inches shorter than the present norm.

250 years of gumbo, boudin, and jambalaya have doubtless contributed to the dimensional assimilation of the Cajuns.