It’s hard for me to imagine a world without Stephen Sondheim. Or without another Sondheim musical. At the time of his sudden death Friday at 91 in his Connecticut home — if a nonagenarian’s death can be characterized as unexpected — he was at work on a new show.

The work in progress, which he talked about on a recent edition of Stephen Colbert’s “Late Show,” had the theater world rhapsodically abuzz. Because anticipating a Sondheim musical was inviting a level of excitement into a musical lover’s life that few other events inspire. His melodic and lyric-writing gifts pulsated with urbanity, compassion and wit: The only advanced degree I will ever earn is the master’s in Sondheim-ology that I gained by going to and listening to his shows over and over and over for more than half a century.

Alone in my bedroom as a New Jersey teenager, I played the cast albums of “Company” and “Follies” until I had the scores memorized, minor chord by chord, impeccable line by line. On weekends in high school, my friend Neil Muhlberger and I took the Suburban Transit bus into New York and stood in the back of the Alvin Theatre — now the Neil Simon — for “Company,” and sat in the last row of the Winter Garden Theatre for “Follies.”

Who knew then that those two 14-year-olds would have tickets to experiences that would color the rest of their lives? That was certainly the case for me, as I journeyed from college to adult life, if you will, side by side by Sondheim. At Yale, I played Hysterium in one of his early hits, the Borscht Belt musical farce “A Funny Thing Happened on the Way to the Forum.” For fun, a classmate, Margery Mark, and I would pull out “A Little Night Music” and in the dorm sing the quippy comic duet for Desiree and Fredrik, “You Must Meet My Wife.” (Okay, we were 19.)

I would sing him, teach him, celebrate him, even roast him. (The roasting was for one late-career clinker he forever tried to unclunk, “Gold!,” which became “Bounce,” which became “Road Show.”)

We were in awe of the deftness of Sondheim’s grasp of character, of plot, of music genres, and how he could take all these threads and spin them with such a refinement of intellect. Never does a Sondheim show sing down to an audience. Maybe that is why he became such a hero to me.

Musicals certainly thrived before Sondheim. But Sondheim’s words and music live on a whole other plane of invention — and that was what dazzled us, show after show. He understood, to stunning effect, the unique gratification of the ideal syllable landing on the perfect note.

Every day a little death,

In the parlor, in the bed.

In the curtains, in the silver, in the buttons, in the bread.

Every day a little sting,

In the heart and in the head.

Every move and every breath,

And you hardly feel a thing,

Brings a perfect little death.

That song, “Every Day a Little Death,” from “A Little Night Music,” is the one that floated into my mind when the news of Sondheim’s death arrived just before dinnertime on Friday. It’s so varnished in brushstrokes of sorrow it could have been written by Emily Dickinson. It’s sung by the secondary character of Charlotte, a woman psychologically abused by her brutish husband in the musical, based on Ingmar Bergman’s “Smiles of a Summer Night.”

I’ve always loved it for its wry evasiveness; Charlotte is keeping her private grief close and at the same time making the pain abundantly clear. The melody starts with a lighthearted effervescence and shifts into a more brooding passage before bouncing back to a lilting sense of resigned surrender. It’s a number that wins actresses awards, as it did for Patricia Elliott, nabbing a Tony in the original 1973 Broadway production.

I love Sondheim in that ruminative key, writing “Anyone Can Whistle” from the show of that title, “Losing My Mind” from “Follies,” “Sorry-Grateful” from “Company,” “No More” from “Into the Woods,” “Move On” from “Sunday in the Park With George.” He’s better known for other theater songs: “Send in the Clowns” from “A Little Night Music,” “Being Alive” from “Company,” “Maria” from “West Side Story,” written with Leonard Bernstein. But it’s the plaintive, introspective, sometimes even bitter numbers that I return to, the ones that feel less like Broadway and more like life.

Contrary to the opining of some, the man had heart. But his intimidating magnitude of cerebration — combined with a complicated spirit that could be generous or impatient — made him a difficult role model. Whole generations of theater composers and lyricists could be thrown off their game by bouts of Sondheim Syndrome: the desire to write with his uncanny rhyming panache or emulate his vast knowledge of music history. (Bradley Whitford’s outstanding portrayal of Sondheim in the newly released Netflix film of Jonathan Larson’s, “Tick, Tick . . . Boom!,” is a timely, affectionate rendition of the rumpled composer who offers encouragement to the struggling Larson.)

I met Sondheim on several occasions, one of them terrifying, a feeling he did nothing to ameliorate. The event was an interview before an audience of 1,000 at the Music Center at Strathmore in North Bethesda. The composer had recently published a deeply illuminating book on songwriting, “Finishing the Hat,” and I was there to grill him for 90 minutes. Alone on a stage with the man I’d worshiped as a kid in the suburbs, I was, to put it mildly, a nervous wreck.

Sondheim had done this sort of performance countless times. I was just hoping not to sound like an idiot. As we stood in the wings, seconds from addressing the throngs who’d come to see him, Sondheim turned to me and said: “You know, the success of this depends entirely on the interviewer.”

Sondheim had a remarkable memory for the progress of his output. Jot by jot, he told us how he put it all together. He was gracious about how much of his work depended on the scripts of the writers with whom he collaborated, George Furth and James Lapine, John Weidman and Hugh Wheeler. He regaled us in elegant fashion, this man who composed the music of my life.

Every day a little death, the man wrote.

Not this one.

Fans standing outside of the Broadway theater named after Stephen Sondheim celebrated his contribution to American musical theater on Nov. 26. (Reuters)