The author, who possesses absolute pitch since the time of his earliest musical experiences at the age of five years, has spent much time in studying this musical phenomenon. Amused by the fact that the most extensive work on “absolute pitch” was conducted by psychologists who did not possess this faculty and that it was done on large groups of students, none of whom possessed this faculty either [For exception see O. Abraham, Sammelbde d. Internat. Musikges 3, 1 (1901) and G. Révész, Zur Grundlegung der Tonpsychologie (Leipzig)], he was convinced that a study by a possessor of absolute pitch on himself and on a large number of other possessors of absolute pitch might lead to different and better results. An original study [A. Bachem, J. Acoust. Soc. Am. 9, 146 (1937)] was conducted on 96 possessors of absolute pitch and 7 more or less musical persons without this faculty for comparison. The work was extended in the course of time to specific related problems which presented themselves through several discoveries.