Professional Orchestration's Orchestral Sketchbook is a companion to the multi-volume Professional Orchestration textbook series, which is a massive revision of the original Rimsky-Korsakov's Principles of Orchestration. Modeled after music papers used in film-scoring in Los Angeles with four pre-ruled bars per page, on heavy 50lb weight white paper. Organized top-down for Piccolo/Flute, Oboe/English Horn, Clarinet, Bassoon/Bass Clarinet, French Horns, Trumpets, Trombones/Tuba, Timpani, Percussion, grand staff for Keyboards, Harp or Vocals, Violins I, Violins II, Violas, Cellos, Basses. Can be used for score analysis or direct composition. Unruled version also available.