21. The piano has always had a special place in music in the United States.
Because one can play on it several notes at once, it can be used in substitution
for a band. This quality has attracted composers; there has been far more music
written for piano, or the keyboards in general, than for any other instrument. And
(Line 5) because a piano can, in effect, accompany itself, for a century it has been the basic instrument for the playing of popular music.
This was especially so during the decades around the turn of the century.
In the years before the First World War (1914-1918), most families in the United
States felt it important to own a piano, no matter how poor they were. People
(Line 10) who could play the piano were welcome visitors and were generally cajoled into
playing the latest popular tunes.
But it was not just in the home that the piano flourished. It was the basic
entertainment tool in cabarets, clubs, and restaurants, just as it is today. The piano,
thus, was central to the social lives of people in the United States, and in the
(Line 15) period between Civil War (1861-1865) and the First World War, there grew up
the considerable industry devoted to it; the popular music business, a huge trade in instructional schools and mail order lessons, and, of course, the selling of pianos
themselves.
Inevitably a large corps of virtuoso professional piano players developed
(Line 20) These “professors” or “ivory ticklers” were not necessarily trained in the classical
European tradition. Most, although not all, either were self-taught or studied with
older ticklers who themselves had little experience with the classical tradition.
Despite the lack of European-style training, many of these players possessed
astonishing technique that, if not well-suited to classical piano compositions,
(Line 25) were exactly right for producing the showy effects with which these professors
impressed audiences and competing pianists. Fast arpeggios, octave runs, and
other great splashes up and down the keyboard were practiced endlessly.
These ticklers were the people who developed and popularized ragtime; it is
no accident that the most populat music of the period was a piano form. And of
(Line 30) course, when jazz came into fashion, they were caught up in this new music.
What does the passage mainly discuss?