In 1901, the Berlin psychologist Otto Abraham published a lengthy study on what he called “das absolute Tonbewußtsein” (absolute tone consciousness), claiming that musical ability is less a natural talent than something learnable—dependent on the imprint of certain tone systems and musical experiences. In place of simple stimulus–response tests, Abraham therefore proposed a completely new method of testing musicality, based on a comprehensive test battery and a detailed questionnaire. This chapter’s investigation of Abraham’s method highlights its underlying epistemology of hearing, with particular attention to the relationship between Abraham’s notion of musicality and his mentor Carl Stumpf’s theory of tone psychology. The chapter then traces later applications of Abraham’s study in the fields of comparative musicology and music education, focusing on testing procedures at the Berlin Phonogramm-Archiv, the Berlin Academy of Music, and, in the shape of U.S. psychologist Carl Seashore’s “measures of musical talent,” American schools and music academies.