their work before assembling the instrument. A scientific explanation includes a discussion of how the properties of the wood determine where the nodes occur, whether the plates move with end or diagonally opposite points rising together or in various mixed modes. This is why the most expensive violin in the world is of Stradivari Violins. Stradivari's lutherie visibly improves, as does his choice of wood. He incorporates an intense red, golden varnish into his instruments. Another important fact was the change in the arching of the top plate, meaning the instrument was less flexible, adding more resistance in the plate so the musician could play deeper sounds with this stronger core. Sizes Children learning the violin often use "fractional-sized" violins: 3/4, 1/2, 1/4, 1/8, 1/10, 1/16, and sometimes even 1/32 sized instruments are used. These numbers do not represent numerically accurate size relationships, i.e., a "1/2 size" violin is not half the length of a full-sized violin. The body length (not including the neck) of a 'full-size' or 4/4 violin is (or smaller in some models of the 17th century). A 3/4 violin is , and a 1/2 size is . Rarely, one finds a size referred to as 7/8 which is approximately , sometimes called a "ladies' fiddle." Viola size is specified as body length rather than fractional sizes. A 'full-size' viola averages , but may range as long as . Such extremely long instruments may be humorously referred to as "chin cellos." Occasionally, a violin may be strung with viola strings in order to serve as a viola. References Bibliography Angeloni Domenico, Il Liutaio - Origine e costruzione del violino e degli strumenti ad arco moderni, legatura tela edit. fig., pp. XXVI-558 con 176 figure e 33 tavole, Milano, HOEPLI, 1923 Simone F. Sacconi, The secrets of Stradivari, Libreria del Convegno in Cremona, Cremona, 1972 Simone Ferdinando Sacconi External links Anatomy of a violin The violin making manual - The complete violin making guide with vectorized images and plans Violin Maker's Workbook compiled by apprentice to master luthier 3D Images of violins created using CT scanning technology Violinbridges - Online archive of bridges of the violin family Violin Making - virtual tour of a violin shop Wire-frame vibration mode animation (Click the "animation" button on Martin Schleske's home page.) The Luthier Helper - Specialized search engine looking only in violin and stringed instrument making, repair and restoration resources