Willgoose said the practice was exposed when Sir Paul McCartney missed his cue during his performance of Hey Jude at the Olympic opening ceremony last year, revealing the entire track had been pre-recorded.
He concludes: "Live music should have an element of risk and an element of danger. There should also be room for improvisation, even if only in small measures. How else are you supposed to be able to tell a good performance from a bad one?"
Deadmau5, the festival-headlining dance producer, has admitted on his blog that he doesn't even mix tracks when he plays live: "I just roll up with a laptop" and "hit a spacebar ... no beatmatching skill required."
Willgoose believes the cost of taking live musicians on the road is forcing struggling rock bands to rely on a concealed laptop. "They put it at the back of the stage because they don't want you to know it's there," he wrote.
The most successful stadium bands rely on technical enhancements. Muse and Coldplay are believed to use playback systems to reproduce their recordings' swelling strings.
Some artists sequence a backing to their video-screen and light show, squeezing the potential for any spontaneity, Willgoose claims.
- The Independent