This music-based variety show turns a young Russian male string quartet into a gurning, pixelated and perpetually kinetic pop-classical boy band. They tap, rollerblade and, for almost 70 increasingly relentless minutes, almost never stop moving while they play.

They're by no means untalented instrumentalists, whose repertoire ranges from Tchaikovsky and Pink Floyd to Phantom of the Opera, Zorba the Greek and Carmen – all generally easily recognised, toe-tapping and clap-along stuff. The sound, enhanced by pre-recording, is sometimes blaring but no one connected with this manic piece of populist light entertainment is likely to be much interested in musical subtleties.

The slim framing device is sporadically brief appearances by a stern instructor who wants his sweaty, almost idiotically eager-to-please charges to toe the line. They quake with grimacing fear until the moment he exits and then carry on full-throttle.

A little of this overextended novelty act goes a long way, but if my fellow spectators are anything to go by that may be a minority view. Most of the faces I scanned during the cast's quick invasions of the seating area seemed to be beaming with pleasure. You too might have a ridiculously enjoyable time. I still can't quite decide if these hyperactive lads are harder to like than dislike, but I left feeling more exhausted then exhilarated.

ZOO Southside, until 29 Aug, 8.35pm, £12 (£11).