second
Basic SI unit of time, one-sixtieth of a minute. It is defined as the duration of 9,192,631,770 cycles of regulation (periods of the radiation corresponding to the transition between two hyperfine levels of the ground state) of the caesium-133 isotope. In mathematics, the second is a unit (symbol ") of angular measurement, equalling one-sixtieth of a minute, which in turn is one-sixtieth of a degree.
second
Major, minor, and augmented seconds.
| In music, an interval of two diatonic notes. A second is an ‘imperfect interval’ (having ‘major’ and ‘minor’ variants). A major second consists of two semitones (for example, C–D). A minor second consists of one semitone (C–D flat). |
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