Newcomer Alex Horne's show, Making Fish Laugh, is a silly and fascinating exploration of the mechanics of comedy. Horne's source text is a report filed by the 1st International Conference on Humour and Laughter, staged in Cardiff in 1976. That report categorises laughter according to a range of stimuli - "Physical or Verbal Incongruity", "Mild Discomfort of Another" - which Horne and his taciturn sidekick Tim put to the test.
It's a rich premise and Horne has fun with it. Audience members are commissioned to chart the show's comic progress on graphs and diagrams. The effect of alcohol on laughter is gauged under not-exactly-laboratory conditions. One punter is subjected to a tickling trial. There's an enjoyable sense that audience and performers are all participating in a shared experiment. Any unruly audience behaviour is swiftly brought under Horne's academic ambit.
There are moments when Horne makes us laugh and makes us aware of why we're laughing in the same instant. There could be more. You sometimes wish his show was being performed by a comedy master rather than a rookie, someone who could more expertly practice what Horne teaches. (Horne has a fine line in rapid-fire, mind-bending quips, but his delivery lacks poise). Nevertheless, this is an involving, playfully provocative debut.
· Until August 25. Box office: 0131-226 2428.
