1780s

Wolfgang Amadeus Mozart | Piano Quartet #2 in E-flat Major, K. 493: I. Allegro

In 1786, early in the era of the pianoforte, “Mozart wrote his two piano quartets for an ensemble essentially as new as the piano,” (Earsense.org). “But for a few random and now obscure composers before him, Mozart became the first to claim a genre that would captivate composers from Mendelssohn and Schumann onwards … Mozart’s “piano” quartets are considered the first in the genre not because they are historically the first, but because they are the historically the first great ones.

When he wrote them, Mozart was at the zenith of his fame as a performing concert pianist as well as a confirmed master of chamber music. The quartets are superbly balanced chamber works with all the craft and intimacy that implies, but they are also magnificent showcases for piano — in essence, chamber concertos, a kinship emphasized by their three-movement designs.”

The first movement’s opening section is in Eb major, but by 1:40 we’ve clearly shifted to Bb major after several hints and feints. The movement eventually concludes in its original key as well, but not before some more delightful harmonic meanderings!

Wolfgang Amadeus Mozart | Symphony #40 in G Minor (K. 550), Movement 1 (Molto Allegro)

“Mozart’s last three symphonies come from the extraordinarily creative summer of 1788,” (RedlandsSymphony.com) “In the space of slightly over six weeks, he composed the Symphony in E-flat, K. 543; the Symphony in G minor, K. 550; and the Symphony in C major, K. 551 …

Of the three 1788 symphonies, the Symphony in G minor, K. 550 (popularly referred to as No. 40, but probably No. 53), is the most original and has had the greatest influence on future composers. Few works from the 18th century are as intense, chromatic, and unconventional … few classical works more clearly point the way toward 19th century romanticism.”

Beginning in G minor, the movement transitions to the relative major key, Bb, for the first time at 0:27. Many other shifts in tonality follow.

Franz Joseph Haydn | String Quartet in F major, Op. 50 #5, 3rd movement

From James MacKay’s paper “Another Look at Chromatic Third-Related Key Relationships in Late Haydn: Parallel Keys and Remote Modulation in Selected String Quartet Minuets” in the journal HAYDN: Online Journal of the Haydn Society of North America 8.2 (Fall 2018): ” … third-related shifts in Haydn’s instrumental music occur earlier than 1790, especially in his string quartet Minuet-Trio movements, often built around a parallel major-parallel minor pairing of keys and their relatives. For instance, in Haydn’s String Quartet in F major, Op.50 no. 5 (Der Traum), third movement, Haydn effects a chromatic third modulation in two stages: touching briefly upon the parallel key (f minor) in the trio, then moving immediately to its relative major, A-flat (i.e. flat III of F major).”

Haydn, who lived from 1732-1809, wrote this string quartet (one of his six “Prussian” quartets dedicated to King Frederick William II of Prussia) in 1787. A nephew of Frederick the Great, Frederick William was one of the most notable patrons of music in eighteenth-century Germany and also an avid amateur cellist, according to the classical record label Hyperion.

This performance is by the Festetics Quartet, known for performing on period instruments. The third movement of this complete four-movement video begins at the 11:43 mark. At 13:20, the shift to Ab major is complete (note: the tuning in this performance is a far cry from A440!)

Wolfgang Amadeus Mozart | Fantasia in C Minor (K. 475)

A good example of a common-tone modulation is presented by Mozart’s Fantasia in C Minor, K. 475 (1785). A shift from B major to D major jumps out at 2:32 via a repeated F# in the melody as the accompaniment briefly pauses. French pianist Ismaël Margain, a graduate of Conservatoire Supérieur de Musique in Paris, is at the keyboard.

Wolfgang Amadeus Mozart | Alla Turca, Sonata #11 in A Major (K. 331)

Wolfgang Mozart’s Alla Turca from Sonata #11 in A Major (K. 331) shifts back and forth between A minor and A major throughout. A piano sonata in three movements, the piece was likely written in Vienna or Salzburg around 1783. The first modulations are at 0:48 and 1:02.

Wolfgang Amadeus Mozart | Piano Sonata #16 (K. 545)

The Piano Sonata #16 (1788) is among the most familiar pieces from Wolfgang Amadeus Mozart‘s works. The piece was described by Mozart himself as having been written “for beginners” and it is sometimes known by the nickname “sonata facile.” The piece is well-known today but was not published during the composer’s lifetime, first appearing in print in 1805.

Starting in C major, the first movement (Allegro) transitions to G major by 0:22 and back to C at 0:47. At 1:32, the movement cycles through a few minor keys as well.