From where do most people know Ragtime?

From the 1973 film "The Sting" with Robert Redford and Paul Newman - nowadays utterly a cult film. The film music, Scott Joplin's Ragtime "The Entertainer" became one of the most popular film hit tunes of all times.

This success showed the popularity potential of Ragtime. Listen (Entertainer Tune)

What is Ragtime?

Ragtime (rag = torn, syncopated time) is a music style that originated in the USA in the nineteenth century and was mainly string instrument music, but later also adapted for piano, bands and orchestras. Today, Ragtime is predominantly associated with piano music.

Definition of Ragtime (based on Bob Milne, www.bobmilne.com): The origins and definitions of "ragtime" are still somewhat mysterious. It is, for sure, a music style that was developed among folk musicians in the southern part of the United States sometime in the 1800s. Since it was a folk playing style rather than a written style, it is impossible to trace it back precisely to its origins.

"Ragtime" was formerly spelled and pronounced "Ragged time". This, technically, means "syncopation" – some notes of the melodies are landing between the beats, rather than on the beats, as was the standard for classical music. This was extremely unusual in those days and was considered, at first, to be of low origin. No one of high upbringing or training would "violate" music in such a way! This style of playing was mostly heard on banjos, mandolins, fiddles, guitars, and stringed instruments of the like. Since the piano was not as popular as the stringed instruments, piano ragtime developed much later.
Although masters of the baroque, classical and romantic eras such as Bach, Mozart, Beethoven and Brahms, all used syncopation to some degree, theirs does not have the feeling of the simple country dance which originated in America. It needs to be noted that simple syncopation was not new at the time; it was just being used differently from before.

Another meaning of the term "Rag" can be traced back into the early 1880s. "Rag" also means "a scrap of clothing" and was being used to refer to, "a scrap of music". It meant, "A short folk tune." This kind of interpretation however would give no acknowledgement to the syncopated timing of the music.

Read more at Wikipedia