:: Well, harmony is often used to generally refer to any long-distance assimilation processes.  So, some general linguistics survey books group them together.  But, of course, countless numbers of other general linguistics books do not even mention consonant harmony.  I have never seen one of these type books mention tonal harmony (but I havent read a lot of these books...). 

 :: There is a general scale article on wikipedia.  But I do agree that it appropriate to treat the major scale types, minor, major, etc., with separate articles.  So, perhaps it is appropriate here, too. 

 :: Additionally, I think that much more can be said about vowel harmony than consonant harmony, which is mostly of the sibilant or coronal type (as far as I know).  So that is a vote for separate articles, too. 

 :: But, I feel that there is a similarity among the various types of harmony that might be worth pointing out.  As I mention above, other authors have thought so, too. 

 :: Re: the unrelatedness of different harmony types.  Would you care to offer an example?  I think that this would be a nice discussion note: a compare & contrast. 

 :: Thanks for your comment. Cheers! -  06:26, 2005 Mar 3 (UTC)