Tonight, the fourth-place network throws its biggest hopes for the season up against most-watched network CBS, which is at its strongest on Monday nights. The success or failure of "The Voice" and the new "Smash" will likely decide whether Bob Greenblatt's first full season as NBC's entertainment chairman is eventually deemed a success or failure.

"The Voice" was a surprise hit for NBC last midseason. In hopes of building huge momentum for its second season, NBC gave its premiere the plum spot after the Super Bowl.

It hopes the show, airing from 8 to 10 on Monday nights, will provide a huge lead-in for the new musical drama "Smash," which enters a 10 p.m. timeslot that has brought dreary ratings for the canceled "The Playboy Club" and "Rock Center," which held it earlier this season.

It's a major risk. CBS's 8-10 Monday comedy lineup, including "Two and a Half Men" and the new hit "Two Broke Girls," has been largely bulletproof this season. At times it has even beat new episodes of other networks' shows with reruns.

Adding to NBC's challenges, Mondays are also home to the long-running ABC hit "The Bachelor" and Fox's "House," as well as the new "Alcatraz," which has earned respectable ratings since its January debut.

CBS's "Hawaii 5-0" at 10 has earned strong ratings, but shed some of the audience for the sitcoms that lead into it. NBC hopes "The Voice" can lure away its audience - or at least capture those uninterested in the island procedural.

"Smash," whose all-star cast includes Debra Messing, Angelica Huston and Katharine McPhee - seems to be the new NBC show closest to Greenblatt's heart. He brought the Steven Spielberg production with him from Showtime when he joined NBC last January. And the network has aggressively promoted it, hoping it will be the second breakout hit on Greenblatt's watch. ("The Voice," the first, was in development before he took over.)

The network also offered the show online and on-demand before the premiere.

Adding to the high stakes for "Smash" is the uncertain history of musical shows - and especially musical dramas. The embarrassing failure of ABC's "Cop Rock" scared networks off from musicals for years, until the a string of movie successes made them seem once again worth the risk. Fox scored a big hit with the 2009 debut of "Glee," though its ratings have slipped in this its third season.

No film has done more for the current comeback of TV musicals than "Chicago," the 2003 Oscar winner for best picture. Not coincidentally, "Smash" boasts the production team behind "Chicago," Craig Zadan and Neil Meron. The production team is just one element of "Smash" that NBC hasn't left to chance.

While ratings will not be in until Monday morning, "The Voice" premiere after the Super Bowl has a strong shot at being the top-rated premiere of the season. It would have to beat the premiere of the reconstructed "Two and a Half Men," which drew 28 million viewers eager to see how Ashton Kutcher would fill Charlie Sheen's shoes.

The down-to-the wire finish for Sunday's Super Bowl between the New York Giants and New England Patriots has a strong shot at beating last year's record of 111 million viewers. (That game beat the previous year's record for most-watched U.S. television broadcast.) That's good news for "The Voice."

But the show also joins a newly crowded landscape for musical competitions. Fox's "X Factor," which arrived in fall, may have cut into "American Idol" ratings that have been down slightly in the show's current, eleventh season since the show returned last month.

In a conference call with reporters last month, "Idol" judge Randy Jackson noted how full the market is becoming.

"I think the space of singing shows is definitely a little crowded right now. They're on year-round now with us, 'The Voice' and 'X Factor' and there's even singing on 'Got Talent.' So you got a lot of singing. So that's what happens when your marketplace gets full. You know what I mean?"

As risky as it is for NBC to air two big hopes on Mondays, the network probably had no better options: Airing on Tuesday at 8 would have put "The Voice" up against "Glee," Though Fox announced last week that "Glee" will take seven weeks off, beginning March 6. Airing "The Voice" on Wednesday or Thursday at 8 would have put it against "Idol."

Jackson, the longest continuously serving music show judge given his eleven straight season on "Idol," sounded magnanimous last week as he said there was room for all the musical shows. He predicted "huge numbers" for "The Voice" after the Super Bowl.

"Listen, they've got a great show and I think there's room for everyone out there," he said. "You will see."

But NBC needs more than just "The Voice" to thrive - it wants a smash from "Smash" as well.

NBC has at least one more wild card to play this season - it announced a March 1 premiere last week for "Awake," an ambitious new drama about a man whose reality is split in two after a car accident. In one reality, his wife survives and son dies. In the other, his son lives and wife dies.

The format could thrill or baffle audiences - but NBC tried gamely to explain it in post-Super Bowl ads Sunday.

(Editing by Chris Michaud)

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