Back in the olden days, we had something called "Orchestras" which comprised dozens of people playing in concert with one another, with a single conductor telling everyone what to do. The sound was pretty amazing, in an era before recordings and big amplifiers. Sure, Orchestras still exist today, but they are an endangered species - many orchestras in smaller cities and towns are struggling to get by, unable to afford to pay union scale for the dozens of people (and support staff) as well as the rent on the huge concert halls needed to perform in.
Brass bands were a popular entertainment at the turn of the last century and every town had a "bandstand" (and many still do, but they have fallen into disuse). On a warm summer night, the local brass band would play John Phillip Souza marches and maybe a few ragtime numbers.
That sort of music fell from favor and new music emerged in the "Big Band" era. Smaller than an orchestra, and perhaps even a Souza band, the Big Bands were the pop music of the 1930's and 1940's. Again, you had to have the cooperation of a dozen or two performers, directed by a "band leader." You see a trend here - and it accelerates.
Jazz bands started out fairly large, but quickly shrank in size to quintets and quartets. The creation of amplified music eliminated the need for a brass section or a string section. Rock and Roll took off - all you needed were a guitarist, a bass player, a drummer, and maybe a keyboardist. Getting people to cooperate became harder to do - and everyone wanted to be a star, not the poorly paid third trombone who never saw the spotlight.
And even in a four-man band, harmony was evasive. The Beatles followed (or created) a pattern that was followed by so many other rock bands - they would become wildly popular and then the infighting would begin - usually over issues like control, attribution, and of course, money. So even a four-man band became unstable, particularly with so much money on the table.
The singer/songwriter trend reduced this further - to one person. Think of Bob Dylan playing the guitar and the harmonica and singing - all at once, like a one-man band - songs he wrote and arranged as well.
We're down to one guy at this point.
Today, we have "rappers" and "DJs" who scream obscenities into the microphone and play "samples" of other people's music. It's gotten to the point where no one wants to be second fiddle (quite literally) to someone else. We are all solo acts today.
What's the point of this? Well, times have changed. Maybe back in the 1940's you would put together a big-band and have a dozen or more members and be able to make enough money in bookings to keep them all fed and housed - not that it was easy or that they lived a life of luxury. Expectations of life were different back then. Few thought they would make big money as a musician and superstars were few and far between - maybe the "front man" band leader or crooner.
Now granted, today and throughout history, there have been backup vocalists and studio musicians, such as the Swampers or the Wrecking Crew - professional musicians paid to sit in the studio and do take after take. They were paid well, but not as superstars. They were paid to remain in the background while some posturing "star" took all the credit.
So what's the point of all of this? Nothing, perhaps. Or perhaps we have become less cooperative over time. At one time, in this country, we had a set of standards of behavior. We had certain expectations and expected the same in others. "Do your own thing" wasn't a thing. You expected to work for someone else and only "make it big" if you got lucky or oozed with talent. Today, people expect to hit the top - win the singing or dancing contest on TeeVee - or go home with nothing.
Everyone expects their 15 minutes of fame - and are pissed-off when they don't get it. And no one wants to be a cog in someone else's machine - that's just being "exploited." And sadly, in many cases, it is. No longer can you afford room and board as third trombone in a big band - you'd end up sleeping in your car.
Others have noted that costs killed the big bands - it was just too expensive, outside of the studio, to tour with an entourage of a dozen musicians, unless you were a big name doing stadium shows and charging $200 a ticket. And they may very well be right about that. But I think there is something else at work as well - the desire today to be independent, to be a lone wolf, rather than part of a pack.
I have to say I am part of that trend - working as an "independent contractor" for the last 20 years or so of my career, from a home office, rarely interacting with others. It took a pandemic to move this model to the masses, and today people are so used to working at home, alone, that they chafe at the idea of going back to the office. Why be a backup singer when you can sing a solo in the spotlight?
I'm not necessarily saying this is a bad thing entirely - personal freedom is a nice thing and all, until you take it to the illogical extreme that "Sovereign Citizens" do. Like it or not, we do need to interact with one another to accomplish great things, or even survive.
Will this trend reverse? Maybe, a bit, but I doubt it. Once you have been off the leash for so long, it is hard to re-acquaint yourself with the harness, hence the push-back to "back to the office" attempts.
No, the big bands are gone and not likely to return. And that's kind of too bad, but all the synthesized trumpets in the world are no substitute for the real thing.