Carolyn Ellis, age 12, of Columbia, Tenn., for her question:

WHEN WAS THE HARP INVENTED?

We don't know when the harp was invented, but we do know that it is the oldest of ail stringed musical instruments. It is also the most important musically of the stringed instruments that are played with the fingers rather than a bow. The harp goes back 4,500 years.

The Bible says the harp was invented by Jubal It was the musical accompaniment for the Psalms of the ancient Jews and was played by David.

The double harp, or David's harp, is played with the fingers and thumbs of both hands. It is a triangular shaped instrument with a sounding board and catgut strings.

The most important development of the instrument was the pedal harp, which many historians say was invented about 1720 by Celestin Hochbrucker. This harp had seven pedals which can make each note of the scale in each octave a half note higher.

In 1810, Sebastian Erard invented the double action pedal harp, the harp most often played today. This harp permits two changes in the length of strings and thus two tone changes.