MTV's Rock Band video game took the stage on Tuesday, a new entrant in the fast-growing genre of musical games that could boost the fortunes of the flagging music industry.

More a rock band simulator than a game, the title takes on the hit Guitar Hero series that has sold millions and become a cash cow for publisher Activision Inc.

Many retailers opened their doors at midnight so gamers could plunk down $170 for a Rock Band bundle that includes the game software and controllers shaped like a guitar, drum set and microphone.

Rock Band is the headline act in Viacom unit MTV's plan to spend more than $500 million on games over the next two years as it expands beyond its traditional TV base.

Rock Band is the crowning achievement of Harmonix, a Boston-based game studio started by MIT students seeking to make the experience of playing music accessible to the masses.

A partnership with accessory maker Red Octane resulted in the hit formula of Guitar Hero, but the teams parted ways as Activision bought Red Octane while MTV picked up Harmonix.

For the first time ever we had the resources to really go for it, Harmonix head Alex Rigopulos told Reuters. For us it's a dream game. It's really sort of everything we've ever dreamed of doing.

It's a dream many gamers apparently share. The band in a box won an average rating of 95 on Metacritic.com, which compiles reviews from different gaming sites and publications.

In Rock Band, four people can play together on guitar, bass, drums and vocals. Players hit buttons on the guitar or tap drums in sync with notes on-screen. Players can also sing along, karaoke-style. If notes are hit accurately, the song plays properly and the band earns points.

TRANSFORMER

Much as MTV's music videos transformed the industry in the early 1980s, industry executives and analysts said, Rock Band may change the way people enjoy music. New songs will be available for download every week, with players able to tailor their game to their favorite genres or bands.

Just as musicians tested the novelty of downloads a few years ago by releasing songs online at the same time as on CD, MTV is working with labels to release playable versions of new tunes alongside their debuts in established formats.

In 10 years people are going to look at idly listening to music the same way as we look at watching a TV show in black and white, said Geoff Keighley, co-chair of the Game Critics Awards that named Rock Band the best game of the industry's annual trade show in July.

Game downloads are attractive to game makers and the music business because they are priced at about $2 -- double the cost of a song from an online store.

I don't really expect it to be a huge source of income for the industry but it is a positive story when they need one, said Billy Pidgeon, an analyst with market research firm IDC.

Activision Chief Executive Bobby Kotick said new songs for Guitar Hero will boost profit margins. Activision has sold more than half a million Guitar Hero song packs. That's only $3 million in revenue, but it's a highly profitable drop at a time when the overall music bucket is shrinking.

MTV, for its part, aspires to build an iTunes for games.

We've moved from initial rounds of discussions with the labels to talking about how we can harness this platform to break new artists and to introduce new music from established artists, Paul DeGooyer, vice president of MTV Games, said in an interview.

DRIVERS NEEDED

The music business badly needs growth drivers. Downloads are expected to more than double over the next five years to $3.4 billion -- more than a third of all music revenue -- but that's partly because the industry is contracting, according to a report released Tuesday by JupiterResearch.

For all its grand plans, Rock Band is still playing the role of an upstart new act that must meet several challenges.

This year, the game is only available in $170 bundles that are nearly twice as expensive as Guitar Hero. Individual instruments won't be offered until next year.

There is also the issue of availability. MTV said it would ship more than a million units this year, but Guitar Hero 3 sold 1.4 million units in its first six days on the market and is enjoying wider brand recognition.

Moreover, Rock Band is only available now for Microsoft's Xbox 360 and Sony's PlayStation 3 consoles but there is no release date yet for Nintendo's Wii, which has been the best-selling game console in 2007.

Other game makers aren't expected to sit still, either.

Electronic Arts Inc, which is distributing Rock Band under a three-year deal, may jump in with its own music game at some point. While EA books the revenue from each Rock Band sale, its share of profits is much lower than if it was publishing its own game.

Asked whether EA was working on its own game, EA Partners general manager David DeMartini praised Harmonix before telling Reuters: That's not to say that we wouldn't at some point be involved in the genre, as this is a huge genre that hasn't reached full potential. We wouldn't rule anything out.

(Reporting by Scott Hillis; Editing by Gary Hill)

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