 His theoretical endeavours would culminate in 1779 with the publishing of his 167-page, four volume work, Della scienza teorica e pratica della moderna musica (On the scientific theory and practice of modern music), just before the end of his life.One of his most frequently cited contributions to theory was his development of a system of Well temperament, known today as "Vallotti temperament", which was one of many systems of instrumental tuning for the accommodation of composition in every key.Specifically, the six diatonic fifths F-C-G-D-A-E-B are all tuned 1/6 of a comma flat, while the remaining six fifths B-F#-C#-G#-D#-A#-F are all tuned pure.