Plenty of seats remain for "Back to Titanic Live in Concert," Oct. 9-10 at the Hollywood Bowl, after tickets went on sale Monday. "Historically, classical concerts don't sell like shows by Bruce Springsteen," said promoter Andrew Hewitt. "But, in nautical terms, we haven't hit an iceberg. We expect a slow, steady sale." . . . Due to financial restrictions in its native Brazil, the band Karnak has canceled its scheduled appearance on Thursday at the Santa Monica Pier. The Los Angeles swing bands Alien Fashion Show and Flattop Tom & His Jump Cats will replace the group at this week's edition of the weekly Twilight Dance Series. . . . A benefit screening of "Big Wednesday" on Wednesday at the Santa Monica Civic Auditorium will mark the 20th anniversary of the release of the surfing film and will raise funds for the Surfrider Foundation. . . . Teen country star LeAnn Rimes returned to the concert stage Saturday in Columbus, Ohio, after canceling three shows last week because of a respiratory infection. . . . Fans of ABC's gritty TV crime drama "NYPD Blue" weren't the only ones surprised by ABC's casting of former child star Rick Schroder, 28, to replace Jimmy Smits. "I feel like I won the lottery," the former "Silver Spoons" star told the New York Daily News.