Len Cariou Photo Courtesy of Aruba Productions

What got in the way of putting the revue together was a busy and varied career that is still going strong at age 78, with Cariou currently a regular on the CBS-TV prime time series "Blue Bloods," in which he plays Tom Selleck's father. That range—from classical theater to musical comedy, then from the near-operatic role of Sweeney Todd to film and TV—appears to be the result of training, deliberate career choices, and a good deal of luck.

It was Cariou's work at the Guthrie that first took him to Broadway, when The House of Atreus played a three-week stand at the Billy Rose (now Nederlander) Theatre during the winter of 1968-69. In 1969, while he was soon to be playing Henry V at the ANTA Playhouse, he auditioned for Applause director Ron Field, who Cariou told me said, "'I like what you did very much. Can you tell me again what you're doing now?' I took him out the stage door of the Alvin, where the auditions were being held, and pointed to my face on the show poster for Henry V across 52nd St. at the ANTA. 'That's what I'm doing now,' I told him." After winning the approval of Applause leading lady Lauren Bacall, he won the part.

But even before it opened to rave reviews and a Tony Award nomination for Cariou as Best Actor in a Musical, Applause led to a more-than-fortuitous meeting. "We were doing a gypsy tour of Applause and Hal Prince was in the audience," Cariou tells me. "He came up to me after the show and told me he'd like to work with me. After he left, Field asked if I knew who that was. I didn't." Prince, who was working on Stephen Sondheim and George Furth's Company at the time, wanted to offer him a replacement role in that show, but the success of Applause made that impossible.

After leaving Applause, Cariou returned to Minneapolis and the Guthrie, but Prince never forgot Cariou and invited him to audition for A Little Night Music, initially for the role of Carl-Magnus but later for the leading role of Fredrik Egerman. "I hesitated because I thought I was too young for Fredrik, but Prince assured me it wouldn't be a problem. 'We have a rewrite and some new songs. Will you take a look at it?' I read it and was stunned by the brilliance of the lyrics for the song 'Now,'" Mr. Cariou tells me before reciting a snippet of Sondheim's lyrics from that number. "Of course I would want to do it." He spent a year in the musical, for which he earned another Tony nomination, and returned to the Guthrie and the classics where that year he played King Lear and directed their production of The Crucible.

I try to tactfully point out that it's more than a short hop from the vocal demands of Charles Strouse's songs for Applause or even Sondheim's music for Fredrik in A Little Night Music to the challenges of the title role Sweeney Todd. "I studied voice with Paul Gavert," Cariou explains, "who was the vocal coach of Victoria Mallory [the original Anne Egerman in Night Music]." Gavert's studio, called The Voice Studio, was long the choice of many of Broadway's top talents and is now owned by Follies original "Young Ben," Kurt Peterson. Cariou's headshot appears prominently on the studio's website.

Cariou's classical acting experience together with his voice training under Gavert prepared him to eventually take on what would be one of the most demanding roles in all of musical theatre. The title role of Sweeney Todd has been sung by opera singers such as Bryn Terfel and Timothy Nolen. Under Gavert's coaching, Cariou developed a range of two octaves. Cariou tells me "I learned you can sing all day if you do it properly."

I asked if he knew as they were rehearsing Sweeney that they were creating a classic. "Absolutely," he answers without hesitation. "We just didn't know if anyone would come to see it," he adds, perhaps recognizing that a nearly sung-through musical about a serial killer and cannibalism might be a tough sell. "A few people left during previews, but most were enjoying it. Sondheim was ecstatic after the preview and shouted 'they got it ... they fucking got it.'" Even so, it took a while for audiences to build. Cariou's Tony win—his first—was one of eight Tonys Sweeney Todd earned a few months later and the musical has built in popularity since then. Cariou left the production after a year and has largely stayed away from the role, though he's played the demon barber in some concerts, notably at London's Royal Festival Hall in February 2000. "You have to move on," he explains—echoing another famous Sondheim lyric.

If the past is any indication, and Cariou tells me the show he'll perform at Chicago's Stage 773 will be exactly the show he did in New York two years ago, we won't hear him sing anything from Sweeney Todd. Reviewing Broadway and the Bard for The New York Times in 2016, Charles Isherwood described a show that mixed Shakespearean soliloquies and sonnets with show tunes, finding thematic parallels between the words of the Bard and the likes of Cole Porter, Comden and Green, Ira Gershwin and Sondheim.

In an era when tastes and philosophies seem so compartmentalized and people hesitate to move beyond their comfortable niches, the evening promises to be a refreshing reminder of the commonalties between two so seemingly different humanities. And the commonalities among humans.