From left, Marty Stuart, Roger McGuinn and Chris Hillman. (Alysse Gafkjen)

The contours of the Byrds’ existence as a band in the 1960s and early ’70s would be familiar to any fan of a major American sports franchise: It was marked by a series of teardowns and rebuilds.

As Roger McGuinn and Chris Hillman, the general managers of this genuinely monumental musical franchise, recounted it Monday night at the Strathmore Music Center, the rebuild that led to 1968’s seminal “Sweetheart of the Rodeo” album was hardly the stuff of careful drafting or in-season war-gaming. Three of the band’s five original members, including a soon-to-be-even-more-famous David Crosby, had split by the end of 1967. The attitude that prevailed on the eve of one of the band’s greatest achievements wasn’t so much “Let’s invent a new genre” as much as it was “What do we do now?”

McGuinn recalled approaching Gram Parsons to come in on piano; he was hopeful that Parsons could play jazzy lines like McCoy Tyner, only to discover he was limited to a few licks in the classic Nashville style of Floyd Cramer. He was hired anyway.

McGuinn, 76, and Hillman, 73, took care to explain that the Byrds’ identification with country music was no “foray,” as a critic might lazily put it, but rather a fitful evolution. Years before “Sweetheart,” they felt they had been granted permission by Beatles songs such as “Act Naturally” and “I’ve Just Seen a Face” to employ country-western rhythms and harmonies: If the Fab Four could do it, why couldn’t they?

To mark “Sweetheart’s” 50th anniversary, McGuinn and Hillman have been joined on tour by Marty Stuart and His Fabulous Superlatives, allowing for an expansive, nearly 30-song set list that featured all of “Sweetheart,” plus most of the Byrds’ radio hits (“My Back Pages,” “Mr. Tambourine Man,” “Turn! Turn! Turn!”) and key album tracks such as “Time Between.” Stuart’s deep feeling for the band’s catalogue, as well as his personal affection for McGuinn and Hillman, was evident. And he played a literal artifact of Byrds history — the electric guitar that belonged to Clarence White, with its famous trademark “string-bender” contraption that enabled the bluegrass picker turned rocker to mimic the sound of a pedal-steel guitar with a downward tug of his shoulder strap.

“Let’s hear it for Clarence White’s guitar!” Stuart said to cheers (and far too humbly: His mastery of White’s unique musical vocabulary owes as much to his own considerable talent as it does to the guitar’s hidden mechanism).

Since this tour is more a celebration than a full-blown reunion — they’re not formally calling themselves the Byrds, after all, with Stuart and his able bandmates doing much of the heavy lifting — it can be forgiven for its occasional creaks and hisses. McGuinn strained to reach the high melody line of “So You Want to Be a Rock ’n’ Roll Star.” He can still deliver the signature electric 12-string riffs — but seemingly no more than that. Hillman, meanwhile, handled Parsons’s old vocal lines with aplomb. (His rendition of “Hickory Wind” was a stunner.) The pair’s narrative passages between songs were a little too obviously canned and at times unforgivably corny. Did we need to be divided into this side and that side for a Pete Seeger-style singalong of “You Ain’t Goin’ Nowhere”? No, we did not.

A mini-set devoted to the late Tom Petty made perfect sense — in addition to being a mega-fan and coverer of the Byrds, he collaborated with both McGuinn and Hillman over the years — but it lasted a little longer than the dessert course it was intended to be. Stuart’s blazing mandolin work on a bluegrass-style “Runnin’ Down a Dream” redeemed a listless cover of Petty’s “Wildflowers.”

So much about the Byrds in 2018 is dormant or departed. But it was an unalloyed joy to see McGuinn and Hillman resurrect this piece of their legacy. “Sweetheart of the Rodeo” was meant to be heard and not merely revered.