There's a Mary Whitehouse Experience sketch where the ubiquitous foursome are dressed up like EMF. Having just come off stage, they pretend to have forgotten to play their one real hit. I'm paraphrasing, but their banter goes something like:

"What else can we play?"

"We've played everything we can."

"Oooh there's one more song, isn't there. What's it's called again?"

A sarcastic David Baddiel interjects with: "You've been to see EMF. They haven't played Unbelievable. Do you think they'll do an encore?"

The sketch illustrates the faintly silly ceremony of the "encore" process, but imagine if they didn't reappear on stage and the house lights went up. You'd think "unbelievable," right?

This was exactly the situation I faced last week at MGMT's comeback gig at Heaven.

"Kids! Kids! Kids!" chanted the braying crowd, after the band departed stage left, in anticipation of one of their biggest songs. But they were left booing after the lights went up, presumably still smarting from the fact that the band decided to play the new, 12-minute psychedelic number Siberian Breaks, instead.

The band's lighter material had been given short shrift in favour of a new transcendental, "no singles" direction. Even when they played Time To Pretend and Electric Feel, they sounded robotic and a bit annoyed, as if they were being forced to recite a really, really long shopping list.

The same thing happened the week before, during Kate Nash's show. Promoting her second album My Best Friend is You (Pam Ayers does Kathleen Hanna), the electrics blew, mid-set. Forced to go acoustic, she announced "I wasn't planning to play this song," before reluctantly launching into her Number 2 hit Foundations.

Last month, the Drums, who haven't even released an album yet, unveiled their new direction during a gig. New direction! Already! After giving a lot of interviews about their love of the Smiths, they played precious little from their spunky surf'n'fun times Summertime EP. The bulk of their set was tracks from their forthcoming debut album. Goodbye B-52s-style silliness, hello Killers tribute band!

Not playing your biggest hits is hardly a new phenomenon. But you usually expect it from seasoned bands who have less to lose, not bands barely into their careers. In refusing to play the songs their fans have paid to hear, they're in danger of appearing rather arrogant.