For 30 years, Ono’s music has been an acquired taste that’s famously difficult to acquire. The album she’s recorded with IMA, “Rising,” is replete with screeches, growls and heavy breathing. You hate it already, right? Not so fast. Thanks to the guys in the band–on tourTimo Ellis plays bass and Russell Simins plays drums–it’s also a surprisingly dextrous rock album, alternately fierce and moving. For Ono, “Rising” is something of a comeback. It’s the first album she’s made in 11 years–years largely spent running the Lennon estate. (Where was John’s “Sgt. Pepper” outfit before you loaned it to the Hall of Fame? “It was here.” In a closet? “Yes.” You weren’t worried about moths? “It was well taken care of.”) For her son, “Rising” is a step into the public eye: “I’ve always been kind of scared of playing music. It’s impossible for anyone to listen to me objectively–it’s impossible for me, sometimes. I watched [half-brother Julian] go through hell, and it instilled a lot of fear in me.” For both mother and son, “Rising” is also a labor of love. It’s the ballad of Sean and Yoko.

Ono still lives in That Apartment in That Building. When you visit the Dakota, you must walk over the stretch of sidewalk where her husband was shot to death and enter the open-mouth of the archway. Which is hard, frankly. Once inside Ono’s front door, you must stoop and remove your shoes. It’s a Japanese tradition, but it has a strange flavor here: as if visiting the apartment with the white piano isn’t intimidating enough, you must enter this holy place kneeling. Ono dispels the solemn air in an instant. She smiles maternally and sits Indian-style on a couch beneath a massive photo triptych of her son as a young boy.

For a long time, the world hasn’t been much interested in Ono. There were grand moments over the last 10 years: a Whitney Museum retrospective of her conceptual art, a formidable, six-disc collection called “Onobox.” Still, Ono seemed an artist in search of a context. Fortunately, rock has become more adventurous of late. Lennon has introduced his mother to edgy bands like Sonic Youth, Cibo Matto and the Beastie Boys. “All these new groups are incredible,” Ono says. “They have incredible power and their way of thinking is so different.” She pauses, almost shyly. “Well, not so different than me, actually.” What Lennon had done was let his mother know that rock had an avant-garde once more. Ono smiles. “I think it was his way of saying, ‘It’s OK to be you again, Mommy.’ "

In person, Lennon is phosphorescent with love and awe for his mother, whom he compares to Miles Davis. But he’s dismissive of his own gifts: “I suck, basically. Well, I’m OK.” Lennon, who’s on leave from Columbia University, seems enormously sweet and jittery, insisting he’s introspective, neurotic and intimidated by everything. “Life is frightening,” he says. “You know what I mean?” He seems to be talking about . . . “Yeah, that’s a biggie. That’s a big one. I mean, I grew up afraid somebody was going to shoot my mom or me. But in New York everybody’s afraid of getting shot. I think part of the process is trying to deal with your fear so it doesn’t inhibit you.” Lennon says one way his mother dealt with her own fears was to introduce him to the world, through the media, when he was a child: “She was worried that if she might ever die, or something, I’d be an orphan. She thought that at least if the world, or Lennon fans, loved me, I wouldn’t just disappear.”

The “Rising” tour–which winds up with shows in L.A., San Francisco and Seattle this week–may also be Ono’s gentle way of nudging Lennon into the world. She has had a few misgivings. “When people say to Sean, ‘How could you do this with your mother?,’ I feel a little pang. Does he feel embarrassed? Is this intimidating for him?I didn’t want to mess up his debut.” She certainly hasn’t. “I feel like I won an all-expense-paid trip to Hawaii,” Lennon says, beaming. “You know what I mean? ‘Go on tour with Yoko Ono! Play sold-out shows to loving audiences!’ I’m so proud to be playing this music. Russell and I were joking: ‘We’re bringing Yoko to the people!’ And it’s true. I’m just so psyched to bring Yoko to the people.”