As a composer, I have found these practical books to be invaluable to me. The Study of Orchestration Samuel Adler A great resource covering all instrumental writing, with sections on contemporary writing techniques. The appendix in the back is a quick reference guide. The Essential Music Reference Library Alfred Publishing Complete with an essential dictionary of music, orchestration, music notation,and rhyming dictionary, this quick reference guide has been a godsend. Dictionary of Percussion Terms Lang/Spivak I think one of the weaknesses of the contemporary composer is the inability to write exciting and appropriate percussion parts. This quick reference helps with defining the proper terms for techniques, mallets, instruments, etc., and will open up the possiblities of the compositional palette. Schirmer Pocket Manual of Musical Terms Another great quick reference guide. Tonal Harmony Kostka and Payne I swallowed this music theory book whole. It is a must for serious composers. Ea...