LaRue, Bonds, Walsh, and Wilson's article traces the gradual expansion of the symphonic orchestra through the 18th century. At first, symphonies were string symphonies, written in just four parts: first violin, second violin, viola, and bass (the bass line was taken by cello(s), double bass(es) playing the part an octave below, and perhaps also a bassoon). Occasionally the early symphonists even dispensed with the viola part, thus creating three-part symphonies. A basso continuo part including a bassoon together with a harpsichord or other chording instrument was also possible.