“The Sopranos” (8 p.m. Sunday, HBO) returns for its fifth season with several new characters and a boatload of unresolved issues. Tony and Carmela’s bitter separation gets decidedly weirder when Anthony Jr. discovers a bear sniffing around the backyard pool (and Tony’s bin of rotting duck food). Like most of the action in this season-opener, the bear scenario is played for both laughs and pathos, and teeters on the brink of the ridiculous without ever descending into pure farce.

In other New Jersey news, Tony and Uncle Junior await the return of several “family” members from their long prison stints. These include Tony’s very close cousin Tony Blundetto (Steve Buscemi). The star of “Ghost World” and “Fargo,” Buscemi directed the famous “Pine Barrens” episode of “The Sopranos” in season three. Buscemi’s character doesn’t show up until the second episode, but is well worth the wait. His arrival only compounds Tony Soprano’s great paradox: As his family and his “family” grow increasingly burdensome, Tony’s feelings of isolation and misery become more acute.

Just when you think you’re comfortable with these characters, understand them and even like them, violence erupts in the most sudden and unsettling manner, reminding you that, for all of the awkward titters, this is still a mob drama, and a challenging and occasionally brilliant show that continues to redefine the gangster genre.

• The country cousin to “American Idol,” “Nashville Star” (9 p.m. today, USA), returns for a second season. Last year’s winner, Buddy Jewell, lived up to the show’s label, selling more records than any other new country artist in 2003. During the debut episode, 11 finalists will be chosen from a field of 20.
• Dawn Wells (“Gilligan’s Island”) is host of “That ’60s Home” (8 p.m. Sunday, HGTV), which glances back at the bright colors, bold new fabrics, and audacious space-age and pop-art influenced furniture designs that defined the flower-power decade. In other nostalgia news, E! presents a five-night flashback to the Clinton era with “101 Reasons the ’90s Ruled” (9 p.m. Sunday through Thursday, E!).

Tonight’s other highlights

• Dennis Quaid stars in the 2000 fantasy “Frequency” (7 p.m., ABC).
• The death of a newborn on “Law & Order: Special Victims Unit” (9 p.m., NBC).
• Colin Firth is host of “Saturday Night Live” (10:30 p.m., NBC), featuring musical guest Norah Jones.
• Kenny Chesney performs on “Live by Request” (9 p.m., A&E).

Sunday’s other highlights

• Scheduled on “60 Minutes” (6 p.m., CBS): former Iraqi opposition leader Ahmed Chalabi; Episcopal bishop Eugene Robinson; college basketball coach Geno Auriemma.
• Janis Joplin (Bonnie McKee) performs on “American Dreams” (7 p.m., NBC).
• Roma Downey and Jacqueline Bisset star in the 2004 drama “The Survivor’s Club” (8 p.m., CBS).
• A forensics-obsessed teen may be behind a satanic rite on “Crossing Jordan” (9 p.m., NBC).