While Vivaldi penned hundreds of concertos, he is most famous for the set of four grouped under the title Le quattro stagioni , or The Four Seasons. The work was popular in Europe throughout Vivaldi’s lifetime; as one critic wrote in 1740, “Who does not know the Four Seasons of Antonio Vivaldi?” Ironically, modern audiences didn’t—until the collection was revived during the 1960s. The Four Seasons presents a fascinating tension between the standard musical structure composers used during the Baroque era and Vivaldi’s creative instincts. All four concertos fulfill the basic requirements of the genre: they consist of three movements (fast—slow—fast) with ritornello (returning or repeating) sections for the orchestra and flashy solo passages. Sonnets published with each concerto drive the musical content, however. While it is unknown whether Vivaldi wrote the sonnets before or after the music, each poem has a three-part structure that corresponds nicely with the fast-slow-fast concerto form.

In the second concerto, L’estate (Summer), the opening Allegro con moto (Energetic, with motion) begins amidst oppressive heat. A few birds manage to sing cautiously despite the blazing sun, yet their halting calls fill the shepherd with dread. The second movement, Adagio e piano—Presto e forte (Slow and soft—Fast and loud), depicts the shepherd’s growing awareness that a violent storm is approaching. The storm arrives in the concluding Presto, with thunder, lightning, and violent hailstorms that flatten the ripened corn.

In 18th- and 19th-century operas, the overture was sometimes an afterthought—perhaps because audience members weren't always expected to be listening—while at other times, it was an integral part of establishing the mood. Mozart's overture to Don Giovanni, composed in 1787, is an excellent example of both. While reveling with friends the night before the opera's first performance, one of Mozart's companions turned to him and remarked, “Tomorrow the first performance of Don Giovanni will take place, and you have not yet composed the overture!" Mozart returned to his room and began writing the work around midnight, while his wife Constanze told stories to keep him awake. By 3:00 am, the overture was finished, and the copyists completed the parts just in time for the opera's opening. The orchestra played brilliantly from pages still wet with ink and without rehearsal. As the curtain rose, Mozart reportedly whispered, "Some notes fell under the stands. But it went well." While Mozart didn't lavish his attention upon the overture, the work cleverly sets the stage. Mozart uses the final banquet scene, at which the statue menacingly appears, as the slow introduction, almost as a reminder that the opera is about Don Giovanni's demise. At the same time, the lighthearted Allegro characterizes the sybaritic, pleasure-seeking Don.

First performed in 1787, Joseph Haydn’s Symphony No. 86 is one of the “Paris” symphonies commissioned at the end of 1784 or the beginning of 1785 by Count Claude-François-Marie Rigoley d’Ogny. D’Ogny ran a fashionable concert series known as the Concert de la loge Olympique (Concert of the Olympic Lodge), connected to the secret society of the Freemasons. The orchestra of the Loge Olympique was huge for its day, featuring 40 violins, ten double basses, and doubled woodwinds, and its audience included Marie Antoinette and her ladies-in-waiting. The musicians dressed accordingly, wearing sky-blue brocaded coats, lace ruffles, and swords. The “Paris” symphonies were extremely well-received; a Mercure de France critic particularly praised "this vast genius … very different from those sterile composers who pass continually from one idea to another for lack of knowing how to present one idea in varied forms.”

Many consider the Symphony No. 86 the best of the “Paris” Symphonies. While Haydn scored the works for strings, one flute, and pairs of oboes, bassoons, and horns, Nos. 82 and 86 also feature timpani and trumpets. This expanded scoring contributes to the work’s intensity. Featuring the usual four movements, the third movement—a Minuet with a lighthearted Trio that sounds like an Austrian ländler—sets up the Finale. Marked Allegro con sprito (Energetic, with spirit), the movement begins with quick, repeated eighth notes from which everything else proceeds. As the Mercure de France critic noted after the performance, Haydn’s genius with “the most rich and varied developments” from simple beginnings is seemingly endless.

In 1723, J. S. Bach was appointed music director and cantor at St. Thomas Church in Leipzig, a position he held for the rest of his career. (Bach was the second choice for the position, as the more famous Telemann had already refused the job). His official duties were immense; during his first six years in Leipzig, Bach composed four cycles of cantatas and the St. John and St. Matthew Passions. Eventually, he had written enough that he was able to turn his attention elsewhere. From 1729 to 1737 (and again from 1739 to 1741), Bach served as the director of the Leipzig Collegium Musicum, a group of professional musicians and university students founded by Telemann in 1704. He also published several more abstract, erudite works, including four volumes entitled Clavier-Übung (Keyboard Practice), which hold the Six Partitas for Keyboard (Vol. I), the Italian Concerto, the French Overture (Vol. II), and the Goldberg Variations (Vol. IV). Another late work along similar lines is the mysterious and unfinished Die Kunst der Fuge (The Art of the Fugue) .

The Art of the Fugue consists of 14 fugues and four canons based on a single theme, heard plainly in the subject of Contrapunctus I (Counterpoint 1). The first of the four “simple fugues,” Contrapunctus 1 is a four-voice fugue on the opening subject. Yet, even within this seemingly rigid framework, Bach creates a narrative arc that builds in intensity and gently backs away. The Art of the Fugue contains several mysteries along with this genius counterpoint. When was it written? Printed in 1751 a year after his death, the incomplete score contains a note where the music stops that says, “While working on this fugue, in which the name BACH appears in the countersubject, the author died.” Watermarks on paper and different versions indicate Bach may have been working on The Art of the Fugue at least nine years before his death, however. Furthermore, each fugal voice is notated on a separate staff. Was the work meant to be played on a keyboard instrument, or did Bach intend it for an ensemble? An advertisement dating from 1751 suggested that the collection was “arranged for use at the harpsichord or the organ,” and the range of the individual voices do not match any wind or string instruments that existed during Bach’s time. Yet, in leaving a score so neatly transferrable to a group of instruments, Bach seems to invite musicians to try, and this is precisely what has happened. From string quartet to saxophone quartet, from the Swingle Singers to an industrial band, The Art of the Fugue has come to life in many guises and at many different times.