txtDefinition=An {\uldb interval}{\v 84848}\'97technically an \'93augmented {\uldb fourth}{\v 91666}\'94\'97 comprising three {\uldb whole-steps}{\v 106473}. The tritone traditionally served to define the {\uldb key}{\v 85386} in {\uldb triadic}{\v 102827} {\uldb tonality}{\v 100566}, for it existed only between the seventh and fourth degrees of the {\uldb scale}{\v 94733}.