The theorbo was apparently an extension of the archlute, its body being larger and the neck containing the second pegbox for the lower strings being even longer. The theorbo could reach a total of two metres in length. There were, however, various other differences, the theorbo often being strung with single strings and not in courses. Its tuning was also individual in that the first two strings were tuned an octave lower, this occurring because the main neckpiece was approximately 20 centimetres longer than the archlute's. The third string was therefore the highest. Even though the instrument seems to have been almost specifically used for continuo work, there are some instances of its use as a solo instrument.