It’s the time of year for Magnificats. But first, let me clarify that somewhat cryptic title:
Most serious musicians will know Bach’s large orchestral and choral Magnificat, BWV 243. Fewer know the solo organ piece, BWV 733, usually called “Fuga sopra il Magnificat.” It is based on the tune to which Lutherans of Bach’s day would have sung the Magnificat text. But it is not actually a fugue. Probably “fuga” is a copyist’s error, misreading the sloppily written abbreviation “fant”, for “fantasia”.
Anyway, to continue with my habit of complaining about musical professionals who have no business being professional, the theory has been proposed by musicologists that 733 is not, in fact, by Bach, but by Johann Ludwig Krebs. A lot of people have bought into this, and you can find YouTube uploads of this piece (none of which are particularly good, so I’m not including a link) touting the new “scholarship”.
All I can say is: WTF?! The harmonic and contrapuntal language in the piece is so obviously Bach’s! I have never heard a piece and wondered if it was by Bach. There is no mistaking Bach. And there’s no mistaking when it’s not Bach. No other composer has ever written anything that could successfully masquerade as Bach. If you’re a professional musician, you should be able to hear the difference between, say, Bach and Handel, or Bach and J. L. Krebs.
The piece has a clear and well-advised harmonic plan. Each harmonic area is approached and unfolded in Bach’s usual irreproachable manner. And there is the appearance, toward the end, of organic and well-justified “toni contrarii” (or chromaticism, for you non-early-music buffs), which are such a hallmark of Bach’s style.
The musicologists cite the somewhat archaic stile antico language of the piece as evidence that Bach, who would never have written something so drab, is not the author. But the piece is not drab. And Bach wrote in the Palestrina-esque stile antico all the time! There’s the Gratias agimus tibi from the B-minor mass, the first third of the E-flat major fugue (St. Anne), etc.
Krebs was no slouch, but 733 is not his.