“The old priest waltzed with each of the O’Brien children while his pretty housekeeper, Mme Painchaud, operated the Victrola. She was a widow whose husband had been killed at the sawmill. Sliding the disc from its paper sleeve, she carefully placed it on the turntable and started turning the crank. As the needle settled onto the disc, a Strauss waltz began bleating from the machine’s horn, which resembled, Joe O’Brien thought, some gigantic dark flower that bees would enter to sip nectar and rub fertile dust from their legs.” So begins Peter Behrens’s second novel, The O’Briens (Pantheon, March 6, $25.95), an epic family drama about Irish immigrants that spans 1887 to 1960. A Canadian native who now lives in Maine, Behrens, whose first novel, the award-winning The Law of Dreams, dealt with the potato famine, will be at the Irish Arts Center tonight at 7:30 to launch The O’Briens in a special event cosponsored by NYU’s Glucksman Ireland House and the Consulate General of Canada. Behrens will also be at the Center for Fiction on April 9 at 7:00 for a discussion and book signing.