own popes. These unofficial popes are
now known as antipopes. Beginning in
1378, during a period called the Great
Western Schism, there were popes in
Avignon, France, and in Rome. By 1417,
however, the cardinals had agreed on one
pope. Since then, every pope has lived in
Rome.
#More to explore
Roman Catholicism • Vatican City
The pope blesses a gathering of people in
Vatican City.
BRITANNICA STUDENT ENCYCLOPEDIA Pope 125
Poplar
Poplars are fast-growing trees. People
like them for their beauty and the shade
they provide. Aspens and cottonwoods
are types of poplar. Poplars are closely
related to willows.
Poplars grow in many parts of North
America, Europe, Asia, and North
Africa. Many grow in moist, wooded
areas or near water. Poplars come in
many shapes and sizes. At up to 200 feet
(60 meters), the Western balsam poplar
is one of North America’s tallest trees.
Other types grow only to about 100 feet
(30 meters).
Flowers appear on all poplars. The flowers
develop pods filled with tiny seeds.
These pods will open and the fluffy
seeds will float to the ground. Poplar
leaves are oval, heart-shaped, or round.
The top of the leaf is light or dark green.
The underside is fuzzy and either a
lighter green or silvery color. Poplar
leaves flutter in the gentlest breeze.
Poplars have soft wood that is used to
make furniture, particle board, and
paper. Although it is useful in some
ways, the poplar tree can also cause
problems. The roots are always looking
for water. If poplars are planted too close
to water pipes or sewer lines, their roots
will clog them. In addition, poplars have
more insect damage, disease, and rotting
than many other trees.
#More to explore
Aspen • Tree •Willow
Poppy
Poppies are flowers that are valued for
their brilliantly colored blossoms with
papery petals. They are grown as garden
plants and also for their seeds.
Poppies grow in mild climates throughout
the world. Most species, or types, of
poppy grow best in sunny areas with
moist soil. Some, however, can grow in
rocky deserts.
Some kinds of poplar grow tall and narrow.
California poppies grow wild in a meadow.
126 Poplar BRITANNICA STUDENT ENCYCLOPEDIA
Poppies come in different sizes. Some
are tiny plants that grow near the soil.
Others grow to more than 15 feet (4.6
meters) in height. The leaves may be
green or bluish green. Some leaves,
stems, and the pods that hold the seeds
are hairy.
Poppy flowers are shaped like cups and
have four to six petals. They may be red,
orange, yellow, pink, blue, lilac, or
white. Some species have a dark blotch
at the center of the flower. Poppies do
not give off a strong smell.
Most types of poppies have only one
flower on each stem. The flowers close at
night and open in the morning. When
the soil is dry, the seed pod opens and
many small seeds fall to the ground.
One type of poppy produces seeds that
have a nutty taste when dried. The seeds
are used for baking breads and desserts.
In addition, medicine to relieve pain can
be made from the same poppy.
Popular Music
Popular music is any type of music that
a large number of people enjoy. Popular
music, also called pop, is usually topselling
music created by professional
musicians.
Popular music is different from folk
music. Folk music is the traditional
music and songs of common people.
Popular music is also different from classical
music, which is often more formal
or artistic.
Types of Popular Music
There are many types of popular music.
Some of the best-known types are rock,
country, rap, rhythm and blues (or
R&B), dance music, the blues, jazz, and
reggae. People throughout the world
listen to these forms of popular music.
Other popular music is known mainly
in a certain country or region. Often
this kind of popular music is based on
the traditional music of the area. If this
type of music gains popularity around
the world, people call it world music.
It is very common for popular music to
be popular for only a short time. New
songs regularly replace hit songs. Even
types of popular music lose popularity.
The styles of ragtime, vaudeville, big
band, soul, funk, and disco are no
longer as popular as they once were.
However, some songs and styles have
remained popular for many years.
History
Popular music developed out of many
styles of religious, folk, and classical
A popular music act draws a large crowd
at an outdoor concert in Australia.
BRITANNICA STUDENT ENCYCLOPEDIA Popular Music 127
music. In the 1800s concert bands and
traveling musical groups brought popular
music to more and more people.
In the late 1800s and early 1900s the
United States became an important center
of popular music. Songwriters in
New York City wrote many popular
songs. African Americans created jazz
and other new forms of popular music.
In the early 1900s phonograph records
appeared, so people could listen to
music in their homes. Soon the first
radio stations began broadcasting
orchestras playing popular songs.
Rock and roll, a mixture of country and
blues music, appeared in the 1950s.
Rock and roll became wildly popular
with young people. Rock is still the bestknown
form of popular music.
