I had to work hard. Anyone who works as hard will get just as far. - J.S. Bach
2008, April 22
Cross relation
A 'true' cross relation in measure 3 in a chorale from BWV 114.
In BWV 114.7, measure 3 and measure 7, beat 1 to 2 in the tenor and bass have an E flat in the tenor and an E natural in the bass. The NBA edition and the Barenreiter edition of the chorales show a courtesy accidental on the E flat which does not appear in Kalmus or the Budapest edition. I surmise this is to reinforce the unexpected notation of this true cross relation.
So, why might Bach have done this? The phrase is in g minor; the bass starts on the tonic, leaps up to the dominant, climbs by the ascending minor scale to the tonic, then descends by the descending minor scale to the fourth, steps up to the dominant, then falls back down to the tonic where it started. The tenor starts on the tonic, steps down to the leading tone (the raised seventh of the scale), leaps up to the lowered sixth degree of the g minor scale, then steps downward to the tonic, then down to the leading tone, and back up to the tonic. Two very elegant melodic lines.
Listen to the bass line
Listen to the tenor line
When these two melodic lines are played against one another a harmonic progression results, which I speculate might be read as shown in the above analysis.
Listen to bass and tenor together
Listen to the complete phrase
Here is an excellent site for a discussion of harmonic progressions.
Home page for Robert Frank's Theory on the Web.
Wikipedia definition of a cross relation
