Bartók's biographers have often constructed their portraits around his production of original compositions. While this is understandable it leaves gaps in some of the earlier years of each decade of Bartók's adolescence and maturity: 1900-02, 1912-14, 1923-26, 1931-34, 1940-43. Although Bartók did experience occasional periods of despair and self-doubt, and several times depicted himself as an “ex-composer”, he was rarely inactive during this years. Indeed, consideration of that activity is essential to understanding what followed. This paper examines Bartók's reportedly “fallow years”. It surveys his total production of compositions, including arrangements and educational works, against the backdrop of his work as an ethnomusicologist, teacher, and performer, as well as his public and private activities. The author concludes that these years near the start of each decade were important periods of inspirational renewal and led, particularly in 1926, 1934 and 1943, to powerfully fertile periods initiated by leading masterworks. Using Bartók's correspondence the author delves into Bartók's plans during these “fallow years”, and compares Bartók's actual production of compositions in following years with those he initially intended.