the style of the jazz of the 20s, known retrospectively as Dixieland. Used a marked 4/4 beat, triadic harmony, 'sectional' tunes (with numerous separate sections), simultaneous improvisation, largely I - IV - V type harmonies, etc.
Trad or Traditional climbing requires a leader to place his own protection, rather than merely clipping into bolts. The term gained popularity in the late 1980s with the development of Sport Climbing routes-climbs that were pre-protected with bolts.