Joan Clarke, woman who cracked Enigma cyphers with Alan Turing. Read more about sharing. Joan Clarke's ingenious work as a codebreaker during WW2 saved countless lives, and her talents were formidable enough to command the respect of some of the greatest minds of the 20th Century, despite the sexism of the time.
A semitone, also called a half step or a half tone, is the smallest musical interval commonly used in Western tonal music, and it is considered the most dissonant when sounded harmonically. It is defined as the interval between two adjacent notes in a 12-tone scale (e.g. from C to C â¯).9-tone equal temperament distinguishes between the chromatic and diatonic semitones; in this tuning, the chromatic semitone is one step of the scale (play 63.2 cents (helpÂ·info)), and the diatonic semitone is two (play 126.3 cents (helpÂ·info)).
In music theory, the tritone is defined as a musical interval composed of three adjacent whole tones. For instance, the interval from F up to the B above it is a tritone as it can be decomposed into the three adjacent whole tones FâG, GâA, and AâB. According to this definition, within a diatonic scale there is only one tritone for each octave. For instance, the above-mentioned interval FâB is the only tritone formed from the notes of the C major scale. A tritone is also commonly ...