Image copyright Matthew Murphy Image caption Scenes from Show Boat will feature in the new musical, Prince of Broadway

It's impossible to survey 20th Century American musical theatre without coming across one name over and over again: Harold "Hal" Prince.

As a producer and a director, he has been attached to a greater range of critically and commercially successful Broadway musicals than any other individual, with a record 21 Tony Awards as testament.

It has nonetheless taken more than six years to bring Prince of Broadway, a new musical tracing those accomplishments, to its title location, where Prince last worked a decade ago.

A shortage of investors was at one point an issue, astonishingly - or perhaps not so, given the proliferation of jukebox musicals and movie and brand adaptations that have attracted latter-day Broadway producers.

Prince, now 89, was never fazed. "So many of the shows I've done were met with cynicism, initially," he says.

"It was a journey getting West Side Story to Broadway. It was a journey getting Fiddler on the Roof to Broadway."

Image copyright Getty Images Image caption Harold Prince: "I've got the energy - I still feel about 40 years old"

Both of those classics, originally produced by Prince and directed and choreographed by Jerome Robbins, are featured in Prince of Broadway, which is set to open on 24 August at New York's Samuel J Friedman Theatre.

So are several of the groundbreaking musicals that West Side lyricist Stephen Sondheim introduced in the 1970s (Company, A Little Night Music, Follies, Sweeney Todd) under Prince's direction, and two of the London-based Andrew Lloyd Webber blockbusters Prince also helmed - Evita and The Phantom of the Opera.

Co-directed and choreographed by multiple Tony winner Susan Stroman - with whom Prince worked on an acclaimed revival of Show Boat, which is also represented - includes numbers from 17 shows woven together by David Thompson's minimal book, which enlists the nine cast members to give voice to Prince's thoughts and recollections.

The conceit of having performers essentially play Prince, in addition to various characters from the musicals, was developed in Japan, where the show premiered in 2015.

Image copyright Matthew Murphy Image caption Prince won the 1980 Tony Award for best direction for Evita

"A good deal of what I think about my life in the theatre is now spoken by these guys, and women - which is a lot better than having me play me," Prince quips.

"That's the most fun part of the work, that there's so much goddamn talent around. So many great people working in theatre, or trying to."

For Stroman, whose many high-profile stage credits include The Producers and The Scottsboro Boys, the biggest challenge posed by Prince of Broadway was simply narrowing down the material.

"We would meet in Hal's office every morning and go through lists and lists of different songs from so many shows, telling so many incredible stories," she says. "Hal has never been afraid to take chances, to go to places that people previously thought a musical couldn't go - like a Latin-American prison."

That's a reference to Kiss of the Spider Woman, one of two musicals showcased in Prince set in prisons - the other being Parade by Jason Robert Brown, who has provided a new song and arrangements.

Image copyright Getty Images Image caption Prince on Trump: "If you have a diva or a narcissistic star, the atmosphere turns viral."

That a reminder of the social and moral conscience that has driven many landmark musicals arrives on Broadway in this first year of the Trump administration is plainly not lost on Prince.

In a letter to The New York Times, he wrote: "There's a saying in theatre that whoever occupies the star's dressing room creates the atmosphere backstage.

"I've been thinking about that recently in terms of our national trauma, and I believe the star in our dressing room has brought about the epidemic of dangerous mood changes, random episodes of violence and a general malaise in the lives of most Americans."

In conversation, Prince notes: "There have been so many dangerous times in our history. But I will say this - Watergate was a pipsqueak of an event compared with what this country is going through right now. It's the most egregious and unpredictable thing.

"But we'll rise out of it. I have so many heroes now. Every night my wife and I watch Stephen Colbert, and he is masterful - he is right on the money."

Broadway's creative boom

Prince feels similar gratitude to the producers and backers who finally brought Prince of Broadway to Broadway, among them the non-profit Manhattan Theatre Club and Hamilton producer Jeffrey Seller, listed in the playbill as "creative consultant" but "much more than that, God knows", according to Prince.

"I stopped producing a long time ago, but when I was a creative producer, I said that Broadway lacked creative producers," he says. "But right now, I'm surrounded by them. I've never felt more supported and protected than I do with this show."

There are still, Prince accepts, "people who go into producing because they want to hit the jackpot, which is something that never occurred to me - though I guess I hit it on enough occasions to still be here."

He was encouraged by Hamilton's triumph and the subsequent success of another off-Broadway transfer, Dear Evan Hansen, and the surprise Broadway hit Come From Away, both musicals that deal unflinchingly with tragic events and the necessity of human connection.

New projects

"None of them are star-driven productions, and they've all got interesting and unpredictable subjects. They came along at the right time."

Prince says he has no additional projects lined up at the moment, notwithstanding hopeful buzz about a future Broadway revival of Evita. "I want to find something," he says.

"My wife has said to me, 'Before the opening night of [Prince], I want to know what you're doing next.'

"I don't think anything will come up in the next two weeks. But I've got the energy. I still feel about 40 years old. As long as that holds out, I sure as hell want to keep working."

Follow us on Facebook, on Twitter @BBCNewsEnts, or on Instagram at bbcnewsents. If you have a story suggestion email entertainment.news@bbc.co.uk