Short answers, pulled from the story.
The oldest known musical instrument, a bone flute carved from a cave bear's femur, dates to between 43,000 and 82,000 years ago and was discovered in the Divje Babe cave in Slovenia. This artifact potentially created by Neanderthals remains the subject of intense scholarly debate regarding its authenticity. If the flute is authentic, it proves that a musical culture existed during the Middle Paleolithic period.
The most remarkable surviving example of ancient Chinese music is the monumental set of 65 tuned bianzhong bells found in the Tomb of Marquis Yi of Zeng, which dates to after 433 BCE. These bells span five octaves and were so complex that they required at least five players to perform. They remain playable to this day and bear rare inscriptions that document their musical theory.
The Sasanian period, spanning from 226 to 651 CE, produced a class of musician-poet minstrels known as gōsān who held considerable status in the court. The most famous of these musicians was Barbad, who along with contemporaries like Ramtin and Sarkash, worked in the service of Khosrow II. These figures served as both performers and chroniclers of history while bridging the gap between the divine and the mortal world through sound.
In the 1570s and 1580s, a group of intellectuals in Florence known as the Florentine Camerata sought to restore the music of ancient Greece and sparked a revolution that ended the Renaissance. Led by Vincenzo Galilei and Giulio Caccini, this group developed a declamatory melodic singing style known as monody which eventually evolved into the first operas written around 1600. This new form marked a radical departure from the modal music of the past and created the first truly international style in European music.
The Romantic period witnessed a dramatic expansion in the size of the orchestra and the role of concerts as part of urban society, transforming music into a more expressive and emotional art form. Famous composers like Wagner, Verdi, and Tchaikovsky led this movement which saw the development of nationalistic fervor in the works of figures such as Dvořák, Sibelius, and Grieg. Between 1890 and 1910, a third wave of composers including Mahler, Richard Strauss, and Puccini built on the work of their predecessors to create even more complex and often much longer musical works.
The 20th century brought about a revolution in music listening as the radio gained popularity worldwide and new media and technologies were developed to record, edit, and distribute music. The invention of musical amplification and electronic instruments, especially the synthesizer, in the mid-20th century revolutionized classical and popular music. Two fundamental schools determined the course of the century: that of Arnold Schoenberg who pioneered atonality and the twelve-tone technique, and that of Igor Stravinsky who constantly reinvented his style.