This is probably not the ideal moment to be interviewing Matisyahu, unless you enjoy the company of fired-up pop stars. Because it's the Tuesday after the Gaza aid flotilla incident and the Chasidic reggae artist and rapper - staying at the Holiday Inn in Brent Cross as he promotes his latest album, Light - is not happy.
The rangy New Yorker, 31 at the end of June, prowls around his hotel bedroom in kippah and green jogging pants. He places his tallit under his crumpled white T-shirt and sits down on the couch. In between mouthfuls of vegan curry, he assesses the events of the weekend.
"Oh boy," he says, fiddling with his grey beard and peyot. "I am blown away by the one-sided media coverage. Whether or not the ships should have been bringing aid to Gaza, those territorial waters belong to Israel - it's internationally agreed. They were warned repeatedly not to go there. But when the Israeli soldiers came onto the ships they were lynched; they were shot, stabbed, and beaten with poles. They were meant to be peace activists and they've got Molotov cocktails! Did you see the footage? It's not Israelis beating up peace activists - they're slamming the soldiers one at a time with metal poles!"
He is shouting now, and fiddling more intently with his peyot.
"Do you honestly believe that, if someone was in the English Channel, the British navy would do anything but blow the crap out of the boat, just blow it out of the water? But still people are going to think Israel behaved horribly. As it is, Israel gives tons of aid to Gaza. And they told the people on the ship to go over to dry land and they'd bring the aid with those people overseeing it. But they [the activists] wanted to instigate whatever they wanted to. It's anarchy." He stops eating for a moment, then looks down. "No other country," he says with a heavy sigh, "would put up with the crap that Israel does."
Matisyahu, born Matthew Paul Miller in West Chester, Pennsylvania, was brought up a Reconstructionist Jew - a group prioritising Jewish culture over religion - and had a regular adolescence - attending rock concerts, dabbling with psychedelic drugs - before immersing himself, aged 21, in Torah study and the tenets of Orthodox Judaism. Since 2004, he has also been a successful performer and recording artist, with gold-selling albums featuring his unique mix of reggae, hip hop, rock, R&B and pop - most recently he appears on the official Fifa World Cup album, Listen Up, with a track called One Day. And although he is happy to detail the evolution of both his faith and music, he rarely, if ever, offers his views on Israel.
Is he a militant Zionist?
"No," he replies, adding tetchily: "What does that even mean? That's getting into bigger questions, and I'm not going to do that. I'm a musician. My whole purpose is to bring people together; it's not about focusing on negative stuff. I just happen to be in England and this [Gaza incident] happened and I see how completely one-sided it is. It's emotional to me because it feels so wrong: that's why I'm speaking about it. I feel there's a lot of anti-Israel sentiment in the world and a lot of ignorance about what Israel is and does. But it's not for me to speak on Israel's behalf."
Instead, he talks about life as a working musician and Chasid. Is it difficult maintaining the principles and practices of Judaism on the road? "Not really," he says. "I've been doing this for five years. Putting on tefilin is easy - you can do it in a hotel room or your bedroom. Ideally, you do it in a shul, and there's always one around.
"Keeping Shabbas isn't hard, either. People aren't religious because it's easy not to be. Like anything it's habitual, and once it's a habit it's no longer hard."
It does sound easy - praying three times a day, even locating 10 Jewish men for a minion in whatever city he happens to find himself. He does not have any Jews in his band or organisation, because then there would be no one to sort out the sound or set up the stage on Shabbat.
He obviously cannot travel during High Holy Days, but even that does not faze him. "Yom Kippur's one day, Rosh Hashanah is two, Pesach is several but it's only the first and last days you can't travel on. Succot, Shavuot - overall that's, like, 20 days out of 365 that you can't travel."
Is the relationship between religiosity and rock'n'roll an unnatural one?
"I don't know because today musicians are so driven," he says, convinced that the thrill-seeking rocker is, like the dinosaur, extinct. "It depends if you're talking about classic rock musician types - there aren't that many left. The musicians I know are all very determined. They're not getting drunk before or after the show, they're not sleeping with a lot of women - they're focused on their job."
Bob Dylan, Lou Reed, the Beastie Boys, the Ramones - Jewish rockers all, and all prone to misdemeanours. How does Matisyahu square their behaviour with their Jewish faith? He doesn't, simply because "they happened to be Jewish but had nothing to do with Judaism" whereas, for him, "Judaism is my life. Everything I do is through the lens of Torah."
Does he lead an ascetic existence? His music is joyous, but how much fun does the married father of two have?
"I enjoy my life," he admits. "I just try not to get carried away with substances. That's not fun; it's abuse.
"I'm a married man and I've got kids, so girls are out. My voice teachers all say alcohol is the worst thing I could do for my voice - so alcohol's pretty much out. And drugs? I prefer to get there [high] without them."
Is that a biblical rule about treating your body as a temple?
"Well, it is, but it's a grey area. You see Chasidim smoking cigarettes all the time… you can be a religious Jew and smoke weed or do drugs and just say: 'I'm not doing anything wrong.' There would probably be a lot of rabbis who'd say that, technically, you're not doing anything wrong."
His recent decision to become a vegan, he says, was as much the result of disgust towards factory farms as it was a strict adherence to Torah principle.
Does he ever feel like an outsider, this Orthodox Jewish reggae-rapper? "Not really," he says softly, smiling a little but still not quite recovered from his mood at the start. "I do what I love, thank God. I get to make music and get inspiration through Judaism. I can see why people might be surprised, because it's not been done before. It's certainly not typical. People are always trying to wrap head their around it. But it's probably simpler than everyone thinks."