Hold onto your hats and your wallets – it’s the biggest regular tourist drawcard in Siem Reap, apart from the temples.

It’s the weekly free Saturday night concert by the offbeat Dr Beat, aka Beatocello, aka Dr Beat Richner, founder and director of the Kantha Bopha hospitals in Cambodia, including the Jayavarman VII Children’s Hospital in Siem Reap, the venue for the concerts.

Richner, who started performing his concerts in Siem Reap in November 1999, is an oddity – he’s the most famous Siem Reap resident with a daunting international presence, and yet he’s an invisible entity in the social fabric of the town itself.

I’ve lived in Siem Reap for two and a half years and have never sighted the good doctor outside of the hospital – he seems to attend no functions, stroll along no boulevards, nor is he known to venture into local haunts such as supermarkets, bars or cafés.

Yet his face is plastered everywhere in town, on lavish four-colour posters, billboards and banners.

He’s loved and revered internationally, yet reviled by many in Siem Reap. Conspiratorial stories about the doctor shoot across town like lightning flashes through the night skies. This despite the incontrovertible fact that the hospital he has built is an amazing achievement, possibly even a modern miracle, and a feat perhaps only overshadowed by his mastery of fundraising.

It seems this local enmity is not about what he does, but how he does it. Despite the cute and cuddly avuncular images on his many posters, he’s deemed by locals to be autocratic and dictatorial, and many of his methods are frowned upon.

Few locals admit to attending his concerts, despite praise heaped on the performances in most guidebooks, and on numerous websites.

Frommer’s travel guide for example says, “Dr Beat (Beatocello) Richner plays the works of Bach and some of his own comic pieces between stories and vignettes about his work … Dr Richner is as passionate about his music as he is about his cause. You’re in for an enjoyable, informative evening.”

For no particular reason, I had never attended a Dr Beat concert. But last Saturday night, together with about 200 tourists, I fronted at the Jayavarman VII Children’s Hospital’s deluxe auditorium for Siem Reap concert number 557.

But it was soon apparent that a Dr Beat concert is not a concert at all.

It’s a sales pitch, possibly brilliant in an unnerving way.

The musical aspect, the cello playing, is minimal. It simply intersperses an emotive, and at times slightly paranoid, spiel by the good doctor, mainly to raise funds, but also to pay out on all those he has deemed as attempting to stand in his troubled way, trapped as he is by his own unappreciated philanthropy. “There is no way to mitigate the pressure,” he tells his audience. “You become a prisoner of your own conscience.”

He is, as he confides to his audience, isolated at his hospital – “isolated in an island of justice, an island of peace, an island of no corruption.”

His “concert” has three elements: live cello playing, a very slick video about his history in Cambodia, and the sales spiel.

A February 2009 article in SMA Magazine, published by the Singapore Medical Association, summed it up succinctly, saying, “His concert is a mix of haunting melodies played on the moodiest of string instruments, unaccompanied.

He shows a video of the story of his first hospital in Phnom Penh. The video shows a younger, slimmer man who looks less troubled. As the video ends, he starts to rant about the social injustices suffered by the people of Cambodia.”

The “rant” is a carefully orchestrated, heart-string-tugging monologue, accompanied by the mewling of Dr Beat’s stringed instrument, all designed to extract “money or blood” donations from the mesmerised audience.

It’s a repertoire of shtick, with a legacy that is part travelling medicine show with overblown rhetoric; part vaudevillian goofball humour and music hall entertainment; and part modern-day branding built around a personality cult.

Richner, who claims he was an entertainer and musician as well as a paediatrician in Switzerland before descending on Cambodia in 1991, knows how to work an audience.

His slogan is “The cello is my weapon”, but really it’s his theatrical prop, lulling an audience into the sales pitch that’s to come.

Late night TV hosts often use audience members as their foils, and Dr Beat used the recent presence of the Chinese ambassador as his foil on Saturday night.

Beat informed the audience that he’d been speaking to the Chinese ambassador, who, he said, “Sat right there recently,” pointing to a seat near the front row. His joking references to her peppered his rhetoric. When he touched on political matters he said he’d go easy on this topic in deference to “the Chinese ambassador”.

He said how he’d changed the format of his show recently in deference to “the Chinese ambassador”, pointing again to where she had sat, saying, “She told me I talk too much.”

From the outset he carefully built a conspiratorial edge to his story, the notion that everybody is against him and his hospital despite it being among the best in the world.

He explained that he would show a film at “no risk” to the audience, at no risk to the hospital, the staff, the patents, at no risk to anybody at all.

He never outlined what this “risk” actually might be, but the mere notion added drama to the evening. Audiences members shifted slightly in their seats, some looked sideways, thinking perhaps that secret police were about to swoop.

But the only police presence in the theatre, oddly enough, was the uniformed policeman who acted as usher, leading people to their seats.

The brief musical interludes the doctor did perform were a mix of Bach renditions and salutes to the exiled Spanish cellist Pablo Casals, with whom Dr Beat identifies.

But the emotional arc of the show reminded me of Tchaikovsky’s “1812 Overture” with its slow, ominous build, switching back and forth from lilting but portentous melodic passages to the clanging clamour of cannon, or in this case the raised voice of Dr Beat outlining the horror, the horror of America’s B52 bombing of Cambodia, the rousing relentless recitation of numbers of bombs dropped, numbers of people slain.

Then the calculated pause. Then another burst of hauntingly tragic plucked licks from his weapon of choice, the cello.

A virtuoso performance indeed – and one that really pays off. Richner told 7Days that of the US$33 million received by the hospital in donations annually, $5 million is “linked” to visits to his concerts.