On Thursday, the Baltimore Symphony Orchestra celebrates its 100th birthday.

There are a lot of assumptions around centenarians. For a person, or a private-sector company, it’s venerable. For an orchestra, it feels normal — as if by attaining the century mark, the BSO has passed into some more rarefied orchestral air and finally arrived.

But these assumptions are based on emotion, not facts. We tend to think of orchestras as very old, and indeed, some are. Consider the Dresden Staatskapelle (1548) and the Leipzig Gewandhaus (1781). In fact, though, the majority of the world’s great orchestras are 19th-century inventions — and probably younger than you think. Which is older: the Berlin Philharmonic, the London Philharmonic, or the New York Philharmonic? (Answer: the New York Philharmonic, founded in 1842 — the same year as the Vienna Philharmonic. Berlin followed 40 years later; the London Philharmonic was not founded until 1932.)

In fact, the European orchestral tradition has continued to evolve. A number of the orchestras we consider the world’s best are younger than the National Symphony Orchestra, which the principal horn player, Abel Pereira, described to me as a “young orchestra,” because it was founded in 1931. Yet the NSO is older than four of the five major orchestras that Washington Performing Arts is bringing to Washington this spring. The elite Bavarian Radio Symphony Orchestra, a precision machine and one of the best in the world, was founded in 1949. The Budapest Festival Orchestra didn’t become a full-time ensemble until 1992. Both the Orchestre National de France and the current incarnation of the Montreal Symphony Orchestra began in 1934. The oldest orchestra of the five is the San Francisco Symphony. Founded in 1911, it’s the same age as IBM.

[Ivan Fischer leads Budapest Festival Orchestra where NSO couldn’t go]

Indeed, if anything, American orchestral culture shows slightly less youth than its European counterparts. The orchestras we tend to think of as America’s greatest, from Boston and Chicago to Minnesota and Los Angeles, were all established before 1920.

Does America cling more tightly to tradition? The idea that old is good can certainly be read between the lines of a lot of the orchestral programming with the steady release of announcements for the 2016-2017 season: orchestras, this year, seem to be playing it safe. Brahms and Beethoven and Tchaikovsky are all great. But with a few exceptions, like the New York Philharmonic, the prevailing view seems to be that they’re all that audiences want — that the less-known is going to scare people away.

Easy for me to say. I don’t have to sell tickets, and if I did, I might understand that the presenters have reason for their fears. When I write about performances of chestnuts — the NSO, for instance, preparing European repertoire for its current European tour — readers write to ask why the programming can’t be more adventurous, more contemporary, more American. And yet when the NSO did have an American music director, Leonard Slatkin, who labored energetically for years to make American music by living composers a significant part of the orchestra’s diet, people complained mightily; I still hear from longtime NSO attendees who shudder about it. New repertory wasn’t the only problem people had with Slatkin’s tenure, but it’s unfortunate that this aspect of his work is seen as a problem at all. (The Kennedy Center and Washington Performing Arts will be testing this with their Shift Festival of American orchestras in 2017.

[Four orchestras in five acts: Shift festival announces lineup.]

The BSO’s centennial program in some ways reflects the caution that seems to dominate the contemporary climate — although to give it credit, it only includes music written since the orchestra’s founding. But it plays it as safe as you possibly can with that limitation, including Ravel’s “Bolero,” Gershwin’s “Cuban Overture” and a suite from “West Side Story” with the ubiquitous violinist Joshua Bell. On the bright side, it also includes pieces by Mason Bates (“Mothership”) and Kristin Kuster — whose piece, a world premiere, is the first of 10 centennial commissions by the company Classical Movements that the BSO will present over this season and next. If your goal is to emphasize newer American music while pleasing all your patrons, including your presumably more traditional core constituency, you could do a lot worse.

Now the Baltimore Symphony Orchestra, along with most other orchestras in the 21st century, is faced with the challenge of reinventing itself for the next 100 years. But what does reinvention mean in a field that appears to prize tradition above all else? For some it means experimenting with programming, concert formats and repertory — like the BSO or Alan Gilbert’s New York Philharmonic, which has put costumes on players for “Petrushka,” experimented with semi-staged opera and started new-music programs including a much-vaunted Biennial.

[ How orchestras are embracing multimedia concerts .]

Yet conventional wisdom is cautious. The main thrust of orchestral initiatives in the 21st century — in which the BSO is a national leader — remains not finding new ways to approach the art, but rather new ways to perpetuate the existing tradition — that is, finding new audiences for the same thing.

Hence the focus on the kinds of programs at which the BSO excels: Orchkids, establishing music training in inner-city schools in hopes of improving children’s lives, or the Academy, a (paid) summer music camp at which adult amateurs can have intensive teaching and playing sessions with musicians from the orchestra.

[BSO allows amateur “rusty musicians” to join the orchestra.]

It’s open to question whether any of this makes orchestra concerts more exciting or approachable (and watching the ranks of concert-goers dwindle at orchestral performances in the Kennedy Center Concert Hall in recent months has been rather alarming). It certainly doesn’t change the basic terms of the equation. But there are only so many new tricks you can expect a centenarian to learn. Nor should we forget the fact that we cherish this past for a reason, and that it does give us cause for celebration. Over and over and over and over and over and over.

The Baltimore Symphony Orchestra will hold its centennial gala with Joshua Bell on Thursday night at the Meyerhoff Symphony in Baltimore. It will then play three regular subscription concerts with Bell on Friday and Sunday at the Meyerhoff and on Saturday at the Music Center at Strathmore — of an entirely different and even more conventional program.

eyerhoff in Baltimore. It will then play three regular subscription concerts with Joshua Bell on Friday, Saturday, and Sunday — of an entirely different and even more conventional program.