The writer then presents an arrangement of these proposed measurements in a program, which is also recommended as the outline for a systematic description of the individual in his capacity as a singer. The sensory group of tests includes five tests under pitch, two under intensity, and one under time discrimination. The motor group includes seven tests under pitch, two under intensity, and four under time. The associational group includes two tests under imagery, three under memory, and four under ideation. The affective group contains three tests under musical appeal, and one each under reaction to musical effect and power of interpretation in singing. A copy of this program of tests is given in the Appendix.
In a chapter of his "Psychology in Daily Life,"[6] Seashore describes these special tests. He indicates their significance and suggests approximate norms for those cases for which they are at present available. For the accumulation of many of these norms, and for the conduct of the tests, special and elaborate apparatus and methods are required. For several years the workers in Seashore's laboratory have busied themselves with the problems concerned in the measurement and accumulation of norms for pitch discrimination, vividness of tone imagery, span of tone memory, consonance and dissonance, rhythmic action, intensity discrimination, voluntary control of the pitch of the voice, and the singing of intervals.
Reference to norms thus acquired shows, for example, that in the case of discrimination in voluntary control of the pitch of the voice "a record of .9 vd. means that this ability is within three per cent of the best record for individuals under similar conditions, and that those who have such control are thoroughly qualified to render a high class of music in this respect; while a record of 9 vd. falls within eight per cent of the poorest ability measured, and is characteristic of an individual who cannot sing; whereas 3 vd. represents the average ability of an untrained individual."
Again, in another connection, and with reference this time to the discrimination of tones when heard, the same investigator has suggested that one who can discriminate a difference, from a given standard pitch, of 3 vd. or less may become a musician; one whose threshold falls between 3 and 8 vd. "should have a plain musical education"; one whose discrimination is so poor that 9 to 17 vd. is the measure "should have a plain musical education only if special inclination for some kind of music is shown"; while a measure of 18 vd. or above indicates that the individual "should have nothing to do with music." These suggestions were proposed for individuals of equal age, advancement and general ability.