The string instrument family is perhaps the section of the orchestra that offers the greatest range of expression, intensity, and nuance. It is in essence the foundation of the orchestra. The reason is the number of different instruments that belong to the family. On one side of the family are the bowed instruments like the violin, which require that the strings be played by a bow. On the other end are the instruments that are plucked such as the guitar, the harp, and even the piano.  

    The violin and the cello have developed into the most prominent instruments in the orchestra because of their evocative nature and their range of tones. Violins have existed since the mid 16th century, but it wasn't until the 17th that violin makers like Stradivari perfected the violin's richness and agility. Since then, the musical texture of most orchestras have been defined by the violin. Unlike the violin which is held by the chin and the left hand, the cello is straddled by the musician and rests on the floor. While the violin usually provides the main melodic line, the cello is equally as important because it acts as the background or contrast to that melody. The cello has a lower pitch then the violin, which makes its tones more lyrical and warm. In any one orchestra, the bowed instruments make up about 2/3 of an orchestra.

    The most renowned plucked instrument, of course, is the piano though it doesn't have a real place within the orchestra. The range of notes and its charm have made it the instrument that is most often played solo. For this reason, pianos take a leading role when combined with the rest of the orchestra. Pieces of this nature are called piano sonatas. Guitars are equally as famous, but they have never been fully integrated into the orchetra. Harps, which have been around since biblical times, are consistent invitees to symphonic orchestras since the 18th century. Harps are used to add color and delicacy to the symphony.