'Empire' Books Lenny Kravitz, Alicia Keys & Ne-Yo for Season 2

Chuck Hodes/FOX

Lucious (Terrence Howard) gifts his sons in the special two-hour "Die But Once/Who I Am" Season Finale episode of "Empire" airing on March 18, 2015 on FOX.

The Fox show was upped to 18 episodes for its second season.

Fox's Empire is growing.

The second season of the breakout drama is set to expand to 18 episodes, the network announced Monday.

Chris Rock, Lenny Kravitz and Alicia Keys are among the A-list guest stars already lined up for the new season, Fox TV Group chairmen and CEOs Gary Newman and Dana Walden revealed at Fox's Upfront presentation.

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A notable increase from the musical series' 12-episode first season, the season two rder is still a far cry from the conventional 22-episode broadcast-series season. Considering Empire's massive ratings growth over the first season — the primetime soap pulled in a 6.5 rating among adults 18-49 and nearly 17 million viewers — it only makes sense for Fox to try to get as many new episodes as it can.

However, co-creator Lee Daniels was vocal about his desire to keep the episode count to 12 when he spoke with THR in March — and sounded ready to fight an increase for season two, which was ordered in January.

Empire marks Daniels' first series, and he is the first to admit there have been some bumps along the way. "It was a rough experience — and I don't know [whether it's] one that I would repeat," Daniels said at the Hollywood Radio and Television Society's Hitmakers luncheon in April. "I lost my virginity. I don't know that I would want to lose it again."

'Empire' Soundtrack Debuts at No. 1 on Billboard 200 Chart

Empire's path is similar to that of Sleepy Hollow, which kicked off with a successful 13-episode freshman run. Once it was deemed a bona fide hit, Fox upped the second-season order to 18, but many argued that the show suffered creatively this past year.

More and more, broadcast networks are thinking outside of the typical 22-episode bubble. Fox's The Following, now in year three (but recently canceled), only produces 13 episodes a season, per star and producer Kevin Bacon. Another one of this season's biggest smash hits, How to Get Away With Murder, only ran for 15 episodes -- the most that star Viola Davis' movie schedule would permit.

Another important consideration for Empire is the number -- and quality -- of the original songs created for the series by executive music producer Timbaland, among others. The first Empire soundtrack hit No. 1 on the Billboard 200 just days after the season 1 finale.

On a conference call with reporters Monday to discuss the show's new schedule, Walden teased "amazing guest-stars" lined up for the upcoming second season, as well as the addition of Grammy winner Ne-Yo, who will write original music for the series. Walden said they are optimistic that the second season will not only bring back the show's loyal following from season 1 "but [will] help to expand it as well."

Empire will air Wednesdays at 9 p.m. on Fox this fall.

This article was originally published by The Hollywood Reporter.