Trey Anastasio on his Broadway debut

(CBS News) Writing a musical is a daunting hands-on experience for even the most accomplished Broadway composer, let alone a newcomer. Not so daunting, however, that an iconic rock music figure wasn't willing to give it a go. Anthony Mason takes us backstage:

A few weeks before opening night for a new musical, the cast and production team are making last-minute changes in a rehearsal hall. But the man behind the music is a bit of a "phish" out of water.

Trey Anastasio is making his Broadway debut. "I've said to some friends of mine that it's like trying to parallel-park a cruise ship," he said.

As leader of the rock group Phish, America's biggest jam band, Anastasio is a wizard of musical improvisation. But for a Broadway score, every song has to fit the character who sings it . . . every note has to complement the choreography.

"I did not know the amount of work it was going to take. I didn't know it was going to take four years and, you know, six days a week from 10:00 to 6:00," he said. "It's thrilling, though."

The musical, "Hands on a Hardbody," is based on the 1997 documentary about a group of contestants in Texas trying to win a truck by seeing who can hold their hand on it the longest.

Anastasio has collaborated with lyricist Amanda Green, a Broadway veteran and daughter of Adolph Green, who co-wrote the musical "Singin' in the Rain."

She told Mason that Anastasio has adapted "incredibly quickly" to Broadway. "Yeah, I mean, we act out the parts. We sing them to each other."

The show opens next week. In Times Square, the billboards are already up -- right next to "Annie." "I saw 'Annie' when I was in high school," Anastasio remarked.

But it's HIS name now on the marquee.

"It's hard to wrap my head around," he said. "I used to come to shows when I was 14 and 15 years old with my mom. And I saw 'Chorus Line' and 'Sweeney Todd.' So it doesn't really compute, to be perfectly honest."

In fact, the musical theater bug bit him early, performing in high school productions. "I always lost myself in music from a very, very young age," he said. "It's been my refuge, and it still is."

Refuge from what? "Everything," Anastasio said. "I don't know, you know, whatever's going on. My parents getting divorced . . . "

Fifteen when his parents split, he would build a studio in his father's basement. In 1983, he formed Phish at the University of Vermont with drummer Jon Fishman and bassist Mike Gordon. Page McConnell would join on keyboards two years later.

"Phish never fit into anybody's category," Mason said, "and you didn't try to."

"No. We always felt like lepers," Anastasio said.

And the critics often treated them that way. "I'm not going to lie and say it's a pleasant experience being told that you suck," Anastasio said. "But I was at the concerts, and people were having a great time!"

The band's intensely loyal following swelled. More than 70,000 Phish fans gathered at an old airfield in 1996. Then the critics came around. Rolling Stone magazine called Phish "the most important band of the nineties."

But then, Anastasio says, it got "very dark."

Why did that happen, Mason asked?

"That's a good question," replied Anastasio. "It didn't happen for a long time. But boy, when it did happen, it really ate everything good about our band."

In 2004 Phish split. Anastasio says the driving force behind the breakup was probably him. The reason, he said, was, to "first and foremost, save my life."

Anastasio's drug and alcohol abuse finally caught up with him in December 2006, when he was pulled over by police in upstate New York for driving erratically. "I needed help really badly at that point in time. So I was kind of relieved in a certain way."

The 14-month treatment was hardcore. His job: cleaning toilets in a fairgrounds. "I was up in the drug court program. And I was under house arrest. And I didn't see anyone for a year."

Towards the end his bandmates came to visit.

"It really meant so much to me," he said. "And they made just like a little recording, just the three of them, and they brought it . . . They said, 'Oh, it's only missing you.'"

Anastasio cleaned up, and Phish reunited. Over the New Year they played four sold-out concerts at Madison Square Garden. He has his own band, too, and performs with orchestras around the country.

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Nervously, this past week the composer has been watching audiences react to previews of "Hands on a Hardbody." But after it opens, Trey Anastasio will be on to his next project:

"I love writing music, I just love it," he said. "It's like food."

"Do you have to have something in the back of your head, or even in the front of your head, to keep going?" Mason asked.

"I usually do," he replied. "I don't know if it's a compulsion or if it's healthy. But, you know, it's a gift. If it's of value to someone else other than me, then it's great. What more could you ask for, you know what I mean?"

For more info:

• trey.com (Trey Anastasio's official site)
• phish.com
• "Hands on a Hardbody" (Official Broadway site)
• "Hands on a Hardbody" (Documentary by S.R. Bindler)