This week, it's a very scandalous playlist, as we explore the theme of affairs in classical music. We’re breaking our vows in a show we’re calling “High Infidelity.”

Follow your wandering eye towards our unfaithful playlist below.

• Richard Wagner, Cosima Liszt, and Hans Von Bülow (and Tristan Und Isolde) – While the legendary settings of Wagner's operas often seem worlds apart from reality, the raw, emotional power and intimate relationships of the characters draw audiences to them. Tristan and Isolde, for example, is the retelling of a medieval legend about two ill-fated lovers who begin an affair after both are forbidden from being together. At the opera's premiere in 1859, there was probably nobody who felt the reality of opera's titular characters more than the opera's conductor, Hans von Bülow. While Wagner was working with von Bülow to premiere Tristan and Isolde, he also began an affair with von Bülow's wife, Cosima, who was herself the illegitimate daughter of Franz Liszt. The affair resulted in several children between Cosima and Wagner, and a lengthy divorce case ensued. Though von Bülow complied with the proceedings so that Cosima and Wagner could be legally married, he never spoke to Wagner again after the divorce.

• Felix Mendelssohn and Jenny Lind (and Elijah) – While Mendelssohn’s inspiration for the oratorio Elijah came from the Baroque oratorios of Bach and Handel, his inspiration for the soprano arias in the work came from the famed Swedish soprano Jenny Lind, the so-called “Swedish Nightengale.” In fact, there’s a debate in musicological circles as to whether or not Mendelssohn and Lind had an affair late in Mendelssohn’s life, and many signs point to “yes.” Both Mendelssohn and Lind were in committed relationships, but Lind became Mendelssohn’s muse in the last three years of his life, inspiring an unfinished opera. There is evidence that Mendelssohn even wrote Lind some passionate love letters, threatening suicide if the two couldn’t elope. But these letters were burned after Lind’s death in 1887. Some even speculate that Mendelssohn’s premature death at age 38—just two years after the premiere of Elijah—was a suicide… or at least caused by a broken heart.

• Maria Callas, Aristotle Onassis, and Jackie Kennedy (and Madama Butterfly) – Puccini’s Madama Butterfly is a heartbreaking tale about a soldier named Pinkerton stationed in Japan who marries a young Japanese woman named Cio-Cio-san, only to leave her (and their unborn child) for an American woman when he returns home. In this aria, Cio-Cio-san imagines Pinkerton’s ship returning to her, not realizing the bad news that awaits. Cio-Cio-san became a signature role for the famed soprano Maria Callas in the 1950s, but her fame reached new heights when she became embroiled in her own love triangle involving a sailor. In 1957, Callas began an affair with the Greek shipping tycoon Aristotle Onassis, which caused her to leave her husband, largely abandon her career, and renounce her U.S. citizenship. In 1968, Onassis left Callas to marry former First Lady Jacqueline Kennedy. However, it’s believed that Callas and Onassis continued their affair until Onassis’s death in 1975.

• Gabriel Fauré, Marie Fauré, Emma Bardac, and Claude Debussy (and La Bonne Chanson) – Composer Gabriel Fauré became notorious in Parisian salons in the late 19th century for carrying on several affairs, much to the chagrin of his suffering wife Marie. These included affairs with composer Adela Maddison and, fairly blatantly, with pianist Marguerite Hasselmans. There was even a rumor that all of Fauré’s talented students were actually his illegitimate children! One of Fauré’s most famous, let’s say, “forays” was with singer Emma Bardac. In 1892, Fauré was staying at the home of Bardac, her husband, and their two children. While there, he composed this song cycle La Bonne Chanson for her, featuring poetry of unrequited love by French poet Paul Verlaine. A decade later, Emma Bardac became involved in an affair with a different French composer, Claude Debussy. Both Debussy and Bardac left their respective spouses and married in 1908. Debussy’s piano piece Children’s Corner Suite was written for their daughter.

• Carlo Gesualdo, his wife, and the Duke of Andria – A composer’s fame is usually the result of excellent music, but some composers become just as famous for their actions, if not more so. Such is the case with the jealous Carlo Gesualdo, who murdered his wife and her lover, the Duke of Andria, after catching them, as they say, in flagrante delicto. Gesualdo's wife and her lover had actually been in a fairly public affair for two years before they were caught in the act. It was because they were discovered explicitly in the act of adultery, and because Gesualdo was a nobleman, that he was immune to prosecution. This didn't stop the relatives of the Duke of Andria from seeking revenge, however, and Gesualdo fled to his castle in southern Italy to escape vengeance. It was said that he had all the trees surrounding his palace cut down so that he could see any enemies coming before they arrived at his gates.

• Donizetti's Anna Bolena – Donizetti thought that the tumultuous lives of the Tudor royalty were perfect subjects for his tragic bel canto operas which he called tragedia lirica. Anna Bolena is the first of three operas he composed on the famous queens of the Tudor period, and all of them pull drama from the adulterous relationships between these nobles and their various lovers. The leading roles of Donizetti's Anna Bolena are of course Anne Boleyn, and her first love, Richard Percy, the Earl of Northumberland. Unsurprisingly, complications ensue as Anne and Percy are still in love, and begin a dangerous affair behind the back of the volatile and unstable King Henry, who is himself pursuing an affair with Anne's lady in waiting, Jane Seymour. The opera ends right before Anne and Percy are executed, having been discovered and accused of treason by Henry. Anna Bolena is itself an acknowledgment that Anne Boleyn's execution became one of the most famous royal deaths in history.

• Leoš Janáček and his "Intimate Letters" – For the last eleven years of his life, Janáček carried a torch for Kamila Stösslová, a woman he barely knew (she had once held open a door for him) but with whom he had an imagined affair. Almost daily he would write letters to her, and Janáček’s wife had understandably mixed feelings about this correspondence. This odd relationship put a heavy strain on the composer’s marriage, and much of his music of this period is colored by this strange and unrequited love. Such is the case with his second string quartet, subtitled “Intimate Letters.” Janáček had, at first, planned to title the work “Love Letters,” a reference to the viola d'amore, which was to have replaced the viola in the quartet. The viola d’amore is an obscure baroque instrument with seven bowed strings and seven free-standing strings that sympathetically vibrate. For whatever reason, Janáček decided against including the viola d’amore, and the subtitle of the work changed to “Intimate Letters.”

• Sir Arnold Bax and Harriet Cohen – One of the most famous acts of musical infidelity was the affair British composer Sir Arnold Bax had with pianist Harriet Cohen. In the early 20th century, Bax was considered to be one of the most notable symphonic composers writing in the Romantic style and was even named a Master of the King’s Music in 1942. Harriet Cohen was a famous pianist in her own right, premiering notable works by Vaughan Williams, Elgar, and Bartók. They met in 1914 when Bax was 31 (and married) and Cohen was 19, and the two carried on an affair for nearly 40 years. Cohen became Bax’s muse and most of his works were either written about her or for her to perform. Their affair turned into more of a personal friendship after Bax started a different affair with an even younger woman. In 1992, Bax’s adulterous musical life was turned into a television film by director Ken Russell.