Violin
The violin is the best-known and most popular of the string instruments. 
You play the violin by drawing the horsehair of the bow across the strings, causing the strings to vibrate. The hollow wood body of the violin amplifies the string vibrations, making the famous violin sound. You change the notes with the fingers of your left hand, in effect shortening the vibrating length of the string.
A violin is sometimes called a fiddle—they're the same instrument, differing, some say, only in the kind of music you're playing.
Violin is one of the most expressive musical instruments, capable of producing hauntingly beautiful and emotionally-charged sounds, from slow and sad to high energy and exciting.
Violin is a lead instruments in classical orchestras, but it's played in lots of other musical styles too: jazz, folk, bluegrass, country, rock and roll, etc. It can be played in large groups or small, from full orchestra to rock and country bands to small string ensembles to solo.
Violin isn't a hard instrument to play—it just takes some practice.
Here's an example of some classical violin music:
For more examples of violin music, click on "Violin Performances" on the menu on the left.