(FORTUNE Magazine) – In a business built on relationships, VH1 President John Sykes may be the consummate relationship guy. With a little help from his friends--they include musicians John Mellencamp and Mariah Carey, actors Sean Penn and Susan Sarandon, media heavies Doug Morris and Bob Pittman, President Bill Clinton, and countless others--Sykes has turned once aimless VH1 into the channel for music-loving baby-boomers, a cultural force, and a valuable business for Viacom. While most TV networks have been losing viewers, VH1 has notched 14 consecutive quarters of audience growth; this year it will bring in $300 million in revenue and $100 million in operating profit.

Now Sykes, 44, is repositioning VH1 again, turning away from aging baby-boomers to target 25- to 34-year-olds. Extending the brand, Sykes wants to push VH1 globally, onto radio, the Internet, and perhaps into a magazine spun off VH1's flagship show, Behind the Music. Sykes agreed to let FORTUNE accompany him on a big day for the network--Tuesday, April 11, when VH1 produced a concert billed as Men Strike Back.

9:35 A.M. You can't hurry love. Or Diana Ross. As Sykes and other VH1 executives straggle into a conference room in Viacom's Times Square headquarters, they are still reeling from the trauma of producing Divas 2000, a TV special, two nights earlier. The taping lasted nearly five hours--as Diana Ross, the star, squabbled with the other divas and disappeared into her dressing room for long stretches.

Sykes is philosophical. "Divas are supposed to be difficult," he says. "No one wants to hear that they showed up on time." The show has generated reams of publicity. Even negative reviews, he figures, will help draw TV viewers. In a multichannel world, just getting noticed is a victory. Editors have been working round the clock to get Divas ready to air tonight. With his unquenchable enthusiasm, Sykes tells his staffers, "Tonight we do it again." They try to muster smiles.

10:25 A.M. Fred Graver, who runs VH1.com, tells Sykes that their Website has sold more than 150,000 tickets to an upcoming tour by the rock band KISS. The cable channel promotes the tour in exchange for choice seats, which it sells for a small profit. It's a promising revenue model. "We've arrived at being a television brand, but that's not enough," says Sykes. "We have to be ubiquitous." Next up: fan clubs for 100 VH1 rock bands that will enable fans to buy CDs and tickets. Viacom has filed to sell a stake in the MTVi Group, its Internet sites, in an initial public offering.

10:55 A.M. Sykes is selling a new cable channel, called VH1 Classic, to Curt Henninger, a marketing executive from cable operator MediaOne, who has brought his 10-year-old son to town to see Men Strike Back. The idea is to capture the music-loving baby-boomers who have outgrown VH1 with a channel that plays hits from the 1960s and '70s.

11:45 A.M. Synergy beckons. VH1 has struck a deal with Westwood One, a radio programming company partly owned by CBS, which is merging with Viacom, to launch a radio network for classic rock and top 40 stations. In a cross-promotional bonanza, VH1 will sell news stories, celebrity interviews, and audio versions of TV shows to radio stations. Sykes and Joel Hollander, Westwood One's president, joke about which boss is tougher--Sumner Redstone of Viacom or CBS's Mel Karmazin. Hollander quips, "We're all in the same family. The Manson family."

1:20 P.M. Forget synergy. In for lunch is a crew from NBC's Today, which is trouncing CBS's morning show, to plan a week of programming with VH1 around Save the Music, VH1's public-service campaign that has raised $10 million to promote music education. While joint ventures between cable and broadcast outlets owned by competing media giants is unusual, Sykes and Today show executive producer Jeff Zucker, another pal, are juiced about the cause. Besides, Sykes explains, "Mel has said, 'Make the best deal for your network.'"

Last year Sykes got Hillary Clinton onto Today to assist Save the Music; this year he's trying to book Bill. The Clintons hosted VH1's Concert of the Century on the White House lawn last fall for the campaign, and Sykes has become an unabashed Clinton fan. He has replaced his prized Beatles photos on the wall with grip-and-grin shots from the White House. Says Sykes: "He knows as much about music as he does about defense or anything else. He can cover Celtic to folk to rock to jazz."

2:45 P.M. A quick ride to Madison Square Garden for the Men Strike Back rehearsal. The lineup includes veterans and young stars--Sting, Tom Jones, R&B singer D'Angelo, pop sensations Christina Aguilera and the Backstreet Boys--and before the day is done, Sykes makes a point of thanking every artist. "John is the master of good relations," says VH1's Wayne Isaak, who's in charge of talent for the network, "and that is the gold in the currency of what we do." These artists won't get paid, although they do get valuable exposure. "We don't have assets like factories or ships," Sykes says. "These artists are the soul of our network." In Sting's dressing room, Sykes shares pictures of his kids with the artist, a longtime friend.

4:40 P.M. Sykes heads uptown to his Park Avenue apartment to steal a few minutes with his wife and kids. He calls one of his two crackerjack assistants: "Can you fax my remarks for the Hilfiger thing to my home machine?"

6:45 P.M. Tommy Hilfiger, the leading corporate sponsor of Save the Music, hosts a reception at his men's showrooms on 39th Street. He presents Sykes with a red, white, and blue Gibson guitar, shaped like the White House--similar to a guitar that Sykes and Hilfiger gave Clinton. Sykes tells the crowd, "You can't do anything in this business, in this world, without a great group of supporters."

7:20 P.M. At Tupelo, a nearby restaurant, Sykes entertains cable execs and advertisers.

8 P.M. Sykes watches the concert with his wife, Laurie, and 6-year-old son, Jack, who sings along with the Backstreet Boys. This show is virtually snafu-free, and crowd and performers feed happily off each other.

11:15 P.M. Sykes calls his boss, Tom Freston, CEO of MTV Networks, and tells him the show was terrific. He heads way downtown to party with the stars and VH1 staff, huddling with TV star Jenna Elfman and actor Matthew McConaughey.

12:55 A.M. He's done. "I'll be fast asleep before this party breaks," he says. Sykes' trainer is due in six hours, but he's thinking about canceling.