any of a class of medicinal agents that stimulate the central nervous system, blood circulation, and respiration. In cases of mental and physical fatigue, functioning capacity is increased by the administration of tonics—for example, preparations of ginseng, magnolia vine, pantocrine, or strychnine.
in music, the chief, fundamental note of a key or tonality. In reference to melody, the tonic is a note and is related to the final of the Gregorian chant. In major and minor tonal systems it is a major or minor consonant triad. In 20th-century music dissonant chords may also function as a tonic, as in Scriabin’s use of a complex tonic in his later work. The tonic is the defining note of its corresponding tonality: the functions of notes and chords are determined by their pitch relationships to the tonic. The predominance of the tonic may also be reflected in rhythm and meter; classical composers of the Viennese school, for example, assigned maximum stress to the tonic by means of metrical accents and the placement of tonic chords at crucial points in the musical structure. The tonic of a mode is the most important element in determining that mode’s expressive character, for example, its major or minor nature.
IU. N. KHOLOPOV