Despite being recognized as one of the most important compositions in the twentieth¬ century wind band repertoire, the William Byrd Suite presents many obstacles for the conductor and ensemble members. Since its initial publication in 1924, the piece has contained many discrepancies of pitch, articulation, rhythm, dynamics, and phrase completion that appear in the score as well as the parts. Although the work was reissued by Boosey & Hawkes in 1960 and 1991, many of the original errors remained intact. The sheer amount of inconsistencies causes great difficulties for the musicians involved in the rehearsal process, slowing efficiency and resulting in a frustrating impediment to a quality performance. The primary purpose of this study was the creation of a critical edition of Jacob's William Byrd Suite that eliminates errors of extant editions, incorporates modern instrumentation, and considers the source material. To accomplish this, the present project looks at all sources, including the autograph manuscript, orchestral version, published editions, and errata. The editorial process examines the governing philosophy, subsequent editorial decisions and indications, and the final organization of the parts. The study concludes with the inclusion of the full score of the new critical edition.