Yes, I recall the recent CS thread about it. I was trying to make a funny.
The two biggest ones, ShowCo (known in the 70s & 80s for BIG) and Clair Brothers (known always for quality) merged. They are still huge. But the main difference is that back in the day, every company built their own speakers and had their own way of doing things. That pretty much disappeared with the introduction of packaged systems. EV, JBL, Turbosound, Nexo - each sound company tend to pick one packaged system and standardize on it. This makes doing festivals a lot easier. If you need more gear, you can get it from another company and tie it into the main system without any problems. The different systems sound different, and bands pick what they like, or hire a company to continue to work with engineers they really like.
There are tons of time-lapse videos of load-ins and load-outs on Youtube. Here is one for the Police, for instance, which I would call a “big show” nowadays:
All true, but I’m not sure the total size is that much different. You just have big robot lights spaced further apart on the truss, rather than tons of tightly packed single purpose lights. I’ve seen shows that used two or three dozen of those as the base lighting.
And for those with a taste for such things, there’s the still photos of the truss’ collapse for a Justin Timberlake/Christina Aguilera concert.
And the video footage from when a stage collapsed in South Africa. It just underscores the level of difficulty involved in concert setups.
You need one truck just for the 18’ tall triptych of Stonehenge.
. . .And then when they load the 18" one in there everyone gets pissed. . .
Speaking of which, search Youtube for a show called “Backstage Secrets”. They did several episodes on Rush and the first one on Youtube. Sorry I can’t get there to get a link while at work.
While it focuses on Rush, the question of why so many trucks gets answered pretty effectively. I believe they use 17 trucks for a relatively small stage setup. It is amazing how quickly these types of shows can start setting up in the morning, have show ten hours later, and then be gone a few hours after the show.
That’s highly disputable. There’s nothing country about them other than their records appearing on the country charts.
Anyone remember the Popmart tour by U2? I wouldn’t doubt that they were trucking more equipment from venue to venue than any other concert for that one.
They had the largest screen ever built, what looked like half of the McDonald’s M about 200 feet tall behind the stage, a 50’ tall lemon that moved like a flying saucer … not to mention their stage loadout, etc. And they went to several continents with that tour, including places like Sao Paolo.
I wonder how much equipment, how many trucks, Tony Bennett tours with.
LOL. Thank you. 
On Rush’s site there used to be (maybe it’s still there) an animated video of Geddy Lee being interviewed by his dog. Geddy was reminiscing about the early days of the band when they’d tour around Canada in their beat up Econoline van. The dog says something like, “But you have more than that now, of course?” and Geddy replies, “Yes, now we have two Econoline vans.”
The book “Until the End of the World” focuses on the Actung Baby era U2, and says that their tour of the world and beyond in those days was using basically two setups, because it took so long to get up that they were renting the stadium the day before the show, too, and the crews were leapfrogging each other. This caused concern that a rainy summer in Europe in what, 1992(?) could cause the band to go literally bankrupt. It got the shows in, and now they’re worth about 1/4 billion dollars each. Oh, and the manger, who has scoooorred because he gets 20% commission for not taking on other clients. This means that the band is getting 80% for four members, and essentially they’re five equal partners.
U2 has signed some of the sweetest record deals with Island, and Paul McGuinness (spelling?) is an amazing manager. The band has put on major arena shows since 1987 (and filled the venues before that).
I think Achtung Baby and PopMart were measures in excess “just because.” The whole persona of The Fly during AB and the whole “selling music” theme of PopMart led to the stages being amazingly extravagant.
Maybe Pink Floyd with all their laser equipment and technicians comes close to the quantity of gear, but I doubt surpasses it.
This is funny!
I worked Pink Floyd’s “Momentary Lapse of Reason” tour in '88. If I remember correctly, they had forty trucks* and the load-in started three days before the first of three shows. Stage props included:[ul][li]A twenty foot long flying pig[/li][li]Other inflatables, most were leftovers from The Wall[/li][li]A projection screen, back when no one used projection screens. They played Gerald Scarfe animations throughout the show, and the stage props supported the animations.[/li][li]A hospital gurney, as big as a large pickup, which acted as the climax to a film shown during “On the Run” and which “crashed” into flash pots at stage right when “On the Run” segued into “Time”[/li][li]A mirrored disco ball, twice the width of a semi trailer, that opened into a lotus blossom.[/ul]Multimedia was Pink Floyd’s gimmick, and they loved to do it to excess.[/li]
U2 came into town a few days later with about twenty trucks. Their mirrored disco ball was only as wide as one semi and was left in the truck.
Now you’re telling me that after spending a tour with “mirrored disco ball” envy, U2, metaphorically speaking, bought a Porsche to compensate? We’ll never know for sure why Achtung Baby and PopMart were excessive, but it makes for a great story!
*Actually, PF had two sets of forty trucks. One show would set up/tear down while the other was doing a series of shows.
Awesome, this speaks directly to the question of the OP 
I helped set up and disassemble the stage for the Rolling Stones Bigger Bang tour a couple years ago and they had 3 separate stages so that they could set up in one place while tearing down another one and have on set up to play on.
Can’t remember the exact number but I think it was something like 54 Semis for just the one show here in Missoula. Absolutely ridiculous. Took about a week to put it up.
There has also been no mention of rigging gear or time allocated to hang all the steel said lighting and sound and video require. On any of the tours mentioned above I guarantee at least one or two trucks were dedicated just to carry the rigging gear and motors required to lift it all, not to mention the automation that goes into making such performers fly or disappear into the ground or rotate a drum kit et al.
This coming from somebody who’s loaded in and out most of those shows for 30 years now.
Also power distribution and the requisite cable is another big space eater. 4 0t is heavy and I guarantee for sound, lights, and rigging there’s at least 1k amps of power being distributed at least 3 ways. that’s a lot of transformers, trust me.
Are they going to play Stonehenge again??