Historical background of sad music.
Whilst historians suggest music has been created to express feelings for many thousands of years, it is after it enters Western societies as an art form that we can start to record its journey. From the 16th to 20th centuries, composers such as Brahms, Verdi, Schubert, Bach, Elgar, Mozart, Tchaikovsky and Beethoven created classical masterpieces that purposefully ebbed and flowed through emotions, and in particular often evoked an overwhelming sadness.
Classic FM's list of 'the 10 best classical music tear-jerkers' is topped by Puccini's Sono Andati? from La Boheme, in part due to the tragic story of death and lost love that it represents, and also the mix of subtle suspense and dramatic operatics that the music pours out. Though not an exact science, there are methods expertly used to create feelings of sadness in these concertos, through pacing and pauses, changes in volume and melody, and carefully selected instruments and keys.
Sadness in orchestral music.
These orchestral instruments of woodwind, brass, percussion and strings have since become ingrained within the sound of sad music. Violins and cellos in particular are still often used in all genres of music for this effect. Specific notes have also gained a reputation in songwriting, especially the theory to use minor keys for sad background music and major keys for happy music.
Sad music in pop culture.
Similarly to how the aforementioned artists produced symphonies for operas, music is now essential in soundtracking movies to heighten the viewer's connection to it. Modern examples of songs that became popular due to the heartbreak they represent in the movies include My Heart Will Go On by Celine Dion from Titanic, and Mad World by Gary Jules from Donnie Darko.
The former is a popular ballad, a slow, dramatic sentimental song type and instrumentals, often directly telling a vocal relationship break-up narrative that resonates with the listener. Other mainstream examples of this are showcased on Spotify's 100 strong playlist featuring I Will Always Love You by Whitney Houston and Back For Good by Take That. The latter uses a sparse piano, which is another instrument synonymous for producing a sad song. Even though more upbeat tunes are also played on piano, it has commonly been used by musicians such as John Lennon and Coldplay for their more reflective moments.
Whilst seemingly an unwanted emotion, sad continues to be a highly desired music. The human connection that its pitch, intensity, tempo and rhythm create can actually soothe, and means that it will remain an extremely popular medium in all genres.