A line can be crossed in theatre as therapy, and the wonderful New York singer Anthony Rapp, who starred in the original production of Jonathan Larson’s Rent, goes dangerously close.

His late-night show comes to the Menier Chocolate Factory later this month and I hope they find a way of shaking out the schmaltz before it’s too late. This will be hard, as the whole point of Rapp’s rap is to register his pain at the loss of two significant loved ones: Larson, and his mother.

It starts so well, with the audition for Rent, his portrait of Larson – “I’m the future of musical theatre” the doomed genius declared – and his pulsating delivery of one or two of the show’s great numbers, backed by a punchy onstage band. Musically, the show is a gas.

But lamentation soon turns to mawkishness with the double whammy of two untimely losses, 35 year-old Larson from an aortic aneurysm before the show opened off Broadway in 1996, Rapp’s mother from cancer two years later.

Without You then settles into a seesaw of great numbers and trite confessional, a deadly format not helped by the growing realisation that the show is only aimed at Rent freaks anyway. A sensation in New York, it has never succeeded over here, despite three London productions.

But Rapp is such a good singer, and the lyrical rock songs so powerful in their evocation of an AIDS-blighted Greenwich Village in the 1980s as an update of La bohème, he could possibly change all that: for you come away liking Rapp a lot, and wishing him well, but wishing even more that you’d seen Larson’s distinctive one-off musical instead.