The first sense that this might not be the busiest show in the O2 Arena’s history comes in the concourses: no one is having to queue at the bar before the show. Inside, the top tier is closed, and the arena floor is bizarre: a packed back third, of general admission, and a vast golden circle that is barely a third full. It looks awful, and visitors to the toilet during the show are accosted by arena staff trying to persuade them to take wristbands to go to the front. Thirty Seconds to Mars singer Jared Leto even appeals before the encore for people to go in search of wristbands to come and join the little throng at the front of the stage.

Still, Leto pulls out everything to entertain the people who are there, rather than fretting about the ones who aren’t. He pulls fans on stage and takes requests from the crowd – the planned acoustic segment goes charmingly awry when rather than sticking to the set list, he plays half-remembered snippets of obscurities for a fan at the front. He works tirelessly. Thirty Seconds to Mars may have started as Leto’s side project from his Hollywood career, but they’ve been a successful band for more than 20 years, and he is no amateur.

That said, there’s no point pretending that what they do – an amalgam of alt-rock and emo, plus electronica, and a bit of prog and metal – is very original. It’s all pretty good without ever being spectacular. The less frenetic songs from new album It’s the End of the World and It’s a Beautiful Day – Stuck, and Seasons – sit a little uncomfortably with some of the band’s earlier material, and the crowd reserves its greatest energy for the harder, older songs that close the main set, such as Night of the Hunter and 2005’s The Kill.

Leto is manifestly not the greatest rock star in the world, but no one could come away with anything but admiration for his willingness to make this show work, no matter how tempting it might have been to sulk.