Gordon's music learning theory is based on his research on music aptitude in line with cognitive theories regarding the organization of incoming stimuli [REF].
The 1920s and 30s heralded the creation of aptitude and achievement tests by Carl Seashore, E. Thayer Gaston, H.D. Wing, Arnold Bentley, and Edwin Gordon in an effort to identify students who were most likely to benefit from private instruction [REF].