I have seen it both ways, but I think maybe the best way is to use the original French title (it seems people forget Salzedo was French), and perhaps include an appropriate translation in parentheses. I have always done that on my recital programs, because I like to use the original title of a piece whenever possible, but I also want my audience to know what that title means. And as for the ‘style ancien’, in French that means ‘old style’, not ‘ancient style’ as so many English translations put it. The word ‘ancien’ in French is the common word for old, so it would make more sense to translate it as ‘Variations on a theme in the old(olden?) style’. That’s just my two cents worth, since I am so fond of the French language and I am picky about translation. And I agree that ‘ancient’ makes it sound well, ancient, and it’s in the style more of a classical theme and variations than an ancient Greek song or something.