Even if you could care less for his gloopy music, it's hard not to be a little in awe of Josh Groban. The guy's a world-class ladies' man.
For two-and-a-half years, he stepped out with Mad Men bombshell January Jones. He is also rumoured to have helped pop sexpot Katy Perry get over her divorce from Russell Brand. When you meet him, your first instinct is to give him a high-five and a bro-hug.
"The nice thing about dating someone in the industry is that they understand the pressures of your schedule," says Groban who, unlike most celebs, does not go into lockdown the instant conversation strays towards his personal life.
"That bit where you say 'I love you very much but I have to go and do this now' ... They [other celebrities] understand that. At the same time, they are travelling around the world and you are travelling around the world too. Skype becomes. . . kind of boring after a while."
Groban has sold 25 million albums and, with his puppy eyes and elegant suits, is regarded as one of showbiz's most eligible bachelors. In principle he is not opposed to seeing 'normal' people, he insists. The problem is that women in the real world don't always grasp how crazy an A-lister's schedule can be.
Yes, there's a glamorous side. Day to day, though, it's mostly just work, work work.
"I travel so much, and my job demands so much. Sometimes the schedule is just crazy. That said, it is wonderful to go out with someone who does something completely different. You can learn from what they do."
When romantically involved with a 'civilian', Groban tries hard to downplay his fame.
'I always hope the person hasn't spent their time googling me before I go on a date. I like to know we are starting on a clean slate. I don't know them; they don't know me."
Groban is a curious sort. His music is pious and frankly rather naff – his 2004 chart-topping cover of 'You Raise Me Up' actually manages to out-schmaltz the Westlife version. And yet, off stage he's quite the dude: self-deprecating, down to earth, really funny. If you've ever attended one of his concerts you'll know how hilarious he can be. Should his music career ever peter out, he could easily make a living from comedy.
In fact, he's already dipped his toe in Hollywood, having acted in the US version of The Office and on The Simpsons. Most famously of all, he appeared on American late-night show Jimmy Kimmel Live singing some of Kanye West's more outrageous tweets.
The clip was a huge YouTube success, though word is that Mr West was not amused.
"I'm all for doing something funny," says Groban. "I love off-the-wall humour and taking the piss out of myself. The thing about the Kanye West routine is that it was smart, underneath the silliness. I couldn't believe the response I was getting from people.
"I hope Kanye understands – it was a celebration of his quirkiness. . . But, you know, Kanye lives in another world."
Groban (32) grew up in Los Angeles. He eventually fled the city in order to escape the attentions of the paparazzi. Today he lives in New York where, he reports, celebrities have an easier time.
"Los Angles is celebrity obsessed; New York is ability obsessed," he says. "In New York, you have to be good at something. I like that about New York – if somebody recognises you, it's because they appreciate what you've done.
'LA, on the other hand, has become a town of celeb-watching."
Groban says he has a deep affinity with Irish music. You hear this from American musicians all the time. In this case, it might actually be true: on his previous LP he covered Declan O'Rourke's 'Galileo'; his new album All That Echoes, meanwhile, offers his take on 'She Moves Through the Fair' and 'Falling Slowly', Glen Hansard's weepy ballad from Once.
"I've always loved Irish songwriting, since I was little," he says.
"I discovered 'Falling Slowly' through the movie Once. It was the way people in my country were introduced to Glen and Marketa.
"Me and Glen have emailed back and forth a bit. He's such a nice guy and a talented writer. It's a goal of mine to explore that connection, maybe write with him. I'd love to do it. Of course I'd have to ask him. You need two people for a collaboration. I know I would get a lot out of it."
Josh Groban's album All That Echoes is released now. His All That Echoes European Tour will be at the O2 on June 23. Tickets are on sale now