Editions vary in their notating of baroque ornaments, with some older ones agreeing with the way you play your example (b-c-b). However, newer practice is to start such ornaments on the upper neighbor, which would make your ornament c-b-c-b. The first three notes sound like a triplet.  A judge criticized one of my students for playing it the old way, so I have now switched over. - Although learning all 2-part inventions is an excellent plan, I see no reason to rule the others off limits until you have. Why not sample an easier 3-part invention after you have learned 6 or so 2-part inventions.  At that point you would also be equipped to begin working on WTC (Book I E-minor or D-major, for example).  I believe Bach addresses a wide range of abilities; that is part of what makes these volumes such a treasure.  I hope you enjoy them as much as I have.

Ew.  Good question.  James_neher is correct - there are "new" ways.  I was taught to do the b-a-b way, where the initial b occurs "on" the beat - with the bass note.  This was about 35 years ago.  I would not be surprised that there are more modern interpretations.  

Crashtest,
I studied this invention 17 years ago *gasp*, and I remember playing it with the B-A-B.

About the 2-part, then the 3-part, I think you are right.  Seems sensible.

Well, you learn something new every day. I've never even heard of the triplet (c-b-c)-b interpretation of the ornament on the b. I've only been aware of the c-b-c and b-a-b approaches.

Anyhow, I've learned it as b-a-b, and that seems to make the most sense melodically to me. I have a hard time believing Bach wanted that line ... G-C-B-C to be played: G-C-cbcB-C or G-C-cBc-C. It just doesn't feel right and doesn't sound as good as the more turn-like interpretation. But with Bach, there is always room for dispute in regards to ornamentation, so play what sounds good to you.

SIGH....and in the second paragraph, as well....

From my book, the 1st trill is cbc b (the cbc a tripolet).  I'm quoting a footnote:

"ALL manuscripts show a TRILL here.  The mordent on this note, which appears in the Busoni edition, the Czerny edition and the Mason edition, is withoust foundation. "

I cannot credit my quote, the cover of my book is off.

Karin

Speaking of Bach Inventions,you absolutely MUST check out the Willard A. Palmer edition (I also have his edition of Bach's WTC). In this edition, the suggested ornament articulation is printed above EVERY ornament!  It's awesome!  This is especially good for those who haven't had much experience with ornaments.  I love it, because I don't really have to think when I play !  But it also has markings for suggested phrasing and dynamics (oh no!  You shouldn't use dynamics in Bach's stuff!  That's a SIN and you'll received 20 lashes with a wet noodle!!!)  Seriously, check it out.  About twice the price of a Schirmer (he's SO generic!), but worth it!--Peace, Janice

If you get the "Introduction to Bach's Keyboard Music" by Palmer, you'll find a page with Bach's original instructions on how to play all ornaments but the easiest ones (e.g. the Schleifer/slide, I believe).

If you get Palmer's edition on the 2- and 3-part inventions, you will find a table with the speed that several editors suggest and several performers used. It's mindboggling! I believe there is an invention that Gould plays with MM=240 for the dotted quarter note, while Schiff is playing MM=80, or something like that. Since there are no metronome markings in Baroque, you can choose any speed you like!

There is a lot of info on the web. E.g.,  check out:

http://homepages.kdsi.net/~sherman/WTC.htm

Another thing: the inventions were written in a different tuning scheme. That's why there are only 15 inventions, not 24. To play all that correctly, you'd have to re-tune your piano, but it sounds fine as it is. Check out:

http://www.eunomios.org/contrib/francis1/francis1.html

Of course, everyone nowadays uses dynamics with Bach. Some even argue that, because of that, one doesn't need all those ornaments anymore, because they were intended to draw attention to certain notes. On a piano, this can be done with dynamics, rendering ornaments obsolete.

Don't start a flame war now, please.

ORDER:
(normally, in order of difficulty)

Inventions, Sinfonias, Suites, Partitas (German suites), Preludes and Fugues, Fantasias/Toccatas etc.

There are many exceptions to the rule, but I believe that this is the considered order of difficulty for Bach keyboard works.

Andrew

Don't forget the Goldberg Variations... they were originally for 2 keyboards, but playing them with only 2 hands certainly makes them tedious to learn.