Happy Augmented Sixth Day!

This morning, I was grading an analytical graph of a Mozart sonata that a student had prepared in Excel®. The student had, quite correctly, labeled one measure as featuring an "Augmented Sixth" chord, using the abbreviation "Aug 6th." Well, those who have battled with Microsoft Office products over the years will probably guess what came of that; instead of displaying"Aug 6th" in the little square, the graph said "8/6/2012." Perhaps this serves the student right for not being more specific and calling the chord an "Italian Sixth" (one of the three famous flavors of Augmented 6th harmony), but I couldn't help but be delighted by this bit of AutoCorrect® gone wild, especially because........TODAY IS AUGUST 6th!!!

So, this lovely little coincidence has led me to the realization that August 6th should be celebrated every year as Augmented 6th Day, and I quickly set up a hashtag on Twitter for #Aug6thDay. Unfortunately, it's probably too music-geeky to become a viral sensation (probably?!?), but I've still gotten a few nice responses, including proposals from pianist Geoffrey Burleson for a "San Francisco Sixth" and a "Hungarian Sixth" in honor of Henry Cowell and Franz Liszt. I'm gonna admit I don't know my way around Cowell's music, and I don't know off the top of my head exactly where Liszt's variant occurs - which perhaps will make you feel better if you don't know or remember what an Augmented Sixth chord is. (Augmented Sixth chords are notoriously confusing for music theory students just getting used to normal 'ol triads.)

Well, I'm still supposed to be grading here, so it's hardly the time for a big explanation, but although there are different configurations commonly referred to as Italian, German, and French, what they all share is a downward-pulling note on the bottom and an upward-pulling note on the top that resolve out by half-steps to an octave. Half-step motion is quite important in voice-leading in general, so this double-pull in opposite directions can have a very powerful effect since it's also always going to be using at least one note outside of the key. Thus, when Beethoven in his Waldstein Sonata wants to break through to a B Major chord (the V of E Major, which is where he's headed), he can just turn an A-natural into an A-sharp and, voilà, an Italian-style pull into B from above and below.

[Hear in context here, starting around the 0:28 mark.]

You can sample all manner of Augmented Sixth Chords if you so choose at the very useful Internet Music Theory Database. However, I'm going to end with just one more example, in this case a strikingly unsettled way to begin an extraordinarily beautiful song (#12) from Schumann's Dichterliebe. In this "German Sixth," the initial G-flat in the bass pulls down to F (the V of the song's B-flat Major) while an E in the right-hand leads up to an F. [The C-sharp is what makes this a German Sixth, and it also resolves up by half-step to D.]

This tender introduction sets the tone for a song which is quite simple melodically, but which seems to keep floating from one fragile flower petal (translation here) to another harmonically. Listen to the whole song, and note that this opening figure initiates a heartstopping piano postlude when words finally fail.

The same postlude returns at the end of the final song (when words have failed for good) and sets up the most satisfying but painful page any pianist ever gets to play (in any repertoire).

[should start at the 2:34 mark]

This chord deserves its own day, if only for the first measure of the first Schumann song above. Happy Augmented Sixth Day!

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P.S. Another Twitter acquaintance notes that we've already missed the tritone fun that August 4th had to offer...