A Dictionary of Music and Musicians/Back
BACK. The back of the instruments belonging to the violin-tribe appears to have two distinct functions. It has on the one hand to participate in the vibrations of the whole body of the instrument, and on the other to act as a sounding-board to throw back the waves of sound. This is why the back is usually made of hard wood (sycamore, or harewood), which although not as easily set into vibration as deal, the usual material for the belly, is better adapted to the fulfilment of the above functions. Now and then we meet with a violoncello by one of the old makers with a back of pine or lime-wood. But the tone of such an instrument, however good in quality, is invariably wanting in power and intensity.
The backs of violins, tenors, and violoncellos are shaped after one and the same model: most elevated and thickest in the centre; somewhat thinner and slanting towards the edges. They are made either of one piece, or of two, joined lengthwise in the middle. The back of the double-bass has retained that of the older viol-di-gamba tribe: it is flat, and at the top slants towards the neck. Close to the edges the back is inlaid with a single or double line of purfling, which is merely intended to improve the outward appearance of the instrument.[ P. D. ]