It is always good to double check things that are said about the rhythms.
12 - a dozen - as a number is aesthetically appealing to us and very convenient for a curriculum. It would be a very unlikely coincidence that there are just 12, don't you think? Just for that I would bet there is not that much truth in it.
See for example how the same guy that beerfola provided some links from explains Mamady Keitas created rhythm "bonya":
He says "bonya" means "respect", a fundamental human respect that we got distracted from by different things in modern life, one of them being the quest for prestige. So I looked up this word in my textbook dicitionary and found "bònya" meaning "being or getting bigger" or "size, volume, magnificence". How does that fit with "respect"?
The things the guy says Mamady said about this fundamental human respect certainly appeal to the audience, seeing themselves as members of a drumming community as if they are a big family where love is prevailing instead of fierce competition as in much of the professional modern live. It seems they are told what they want to hear.
Perhaps "bònya" can also have a derived meaning as a kind of respect for all who are grown up, who are "adults" and full members of the community -- opposed to the children, who are not. But given that the Malinke have organized their social life in strong hierarchies, I would guess it is not that simple. "Bònya" as "magnificence" reminds too much on the concept that respect is derived from the magnitude of a person. And the "bigger" that person is, the more respect should be shown to him (for men are fundamentally more respected anyway).
The word "traditional" is not as clear as it might sound at first. What is tradition? Mostly, it is said today, tradition is an invention made by people with a political agenda trying to define for a group of people what they should acknowledge as their shared cultural foundation. And tradition is valued as tradition mostly when the context in which those cultural habits originated have been (almost) lost.
MK, it is repeatedly said, was trying to establish himself as the true guardian of tradition so as to dominate the international market for djembe workshops. He found that tradition was a catch phrase for the people in Germany where he started publishing his knowledge. It is likewise important in Japan and the USA and perhaps a bit less in other modern industrial societies that do have lost their own rootedness in a "traditional" way of life and look at such an imagined alternative life with much nostalgia. Some critical voices even say this (doing African drumming) is basically a commodity bought by the people in the Western world in order to consume a borowed identity as a role play in order to please the ego and establish domination over those "primitive" societies in Africa as if to say: "see, we can be just like you, but you cannot be like us".
Anyway, the picture of "traditional" solos and dance steps is getting more complex when you know that there is no such thing as a curriculum for all Malinke villages and towns, a unified culture as is created in nation building. There was much effort by Guineas first president Seckou Touré to establish such a national culture with the creation of the ballets, of which Mamady is one of the most prominent figures. But it is very conflicted that the figurehead of ballet drumming claims to be the figurehead of "traditional" drumming as opposed to the ballet style as well.
Sometimes, a rhythm is played and/or danced and/ or called different in even the nearest neighboring village. Additionally, even within a village knowledge can get lost or reshaped from one generation to another. Is there only one way to accompany a dance step that fits the step? Is there only one way to interpret a dance step that fits the basic rhythm? No, there is always space for invention, like Tiriba is said to have been a dancer known for an oustanding way of performing the dance to the rhythm with that name. So, in the end, "tradition" is always in a state of flux. If you say "traditional" you should rather point out that what you do has been done by those individuals at this location around that time.
To be clear: nobody in the world has a complete picture about these things. So everybody can claim things are like this or that. But if we could make a survey through the times and all the different villages, how many different ("traditional") ways of soloing and dancing to rhythms would we compile? Hundreds or thousands?
As to the way things are in Mali, I guess MK speaks for Malinke culture only when he claims there are only 12 rhythms with original dance steps and solo phrases. But I remember Daniel (known as "Afoba" here on the forum) as being very
sceptical about the idea of specific solo phrases for rhythms in general. In Mali, we find some unified and common ways of doing things due to the establishment of a shared urban culture in Bamako. Even there, the styles of soloing to specific rhythms varies much in different djembefolas. I guess it is even more pronounced in different villages apart from the capital.
I am looking forward to the DVD, Jean Sebastian, and I am sure we can learn a lot from it. As we can learn a lot from Mamady Keita. We just have to keep in mind that what we learn is just one of many perspectives on a complex thing, just a snippet of the complete picture.