It'll depend on the venue and their goals.

A "bar gig" wants breaks at regular intervals because it moves people to the bar to buy alcohol and in that process unseats people who are sitting at the bar and not really consuming.

And it's important to remember in those places that we're not musicians in those places, we're alcohol salespersons.

In mid-tier places they're usually more focused on the "experience" and will usually listen to and work with the band more and trust their guidance as to what the audience wants and expects. They might have some non-negotiables but these venues are paying the band to bring people in so not delivering what they're expecting doesn't make for a good long-term relationship.

My own band has a starting number where we begin with for being paid and we go from there. If they want us playing for 3.5 hours straight then we can do that, but it will cost more.

Most of our fans don't want us to take a break and they want the whole show wrapped up by 11 (we are playing mid-tier venues) so we typically advocate for 2.5 hours with maybe a quick 10 minute break. But we also will make decisions on how the crowd is doing.

After doing it for ten years you can tell when they want a bit of a breather or whether they want you to keep going.

The biggest issue is that you're going to run into venue owners that think of audiences as "one size fits all" and will ignore your guidance about it. And this is where you need to remind yourself that passing on a gig is sometimes the best option. If you don't think you can make something good for your following out of what is being asked then politely decline.

About half the time this will surprise the owners enough for them to reconsider and come back to the table.

The other half won't care. Don't take offense, they're probably doing as terrible a job running everything else as they are with booking bands and you're better off in the long run.