THURSDAY night and the lights are low, as the four members of ABBA, one of the most successful musical acts in history, take to the stage for the first time in nearly 40 years. Or do they? To the crowd at a purpose-built arena in east London, ABBA’s quartet—Agnetha, Björn, Benny and Anni-Frid—look authentic, their sequinned dresses and feathered mullets swaying to the beat provided by a live band. Yet the singers are computer-generated illusions, captured as they looked in 1979, and their voices a blend of recordings from nearly half a century ago. The virtual “Abbatars”, who played their first concert on May 26, will perform seven shows a week while the human band members stay at home and collect the royalties.

Concertgoers got used to digital performances during the lockdowns of 2020-21, when in-person gigs were not possible. Since the relaxation of Covid rules, people have returned to shows in person. But even as live music roars back, some digital innovations are here to stay. Selling tickets to online video-streams of live gigs has become standard. Online gaming platforms are experimenting with hybrid music-gaming experiences. Musicians are realising that, pandemic or not, there is money to be made in performing gigs without being physically in front of the audience.

ABBA’s extraordinary new show, “Voyage”, goes even further. It demonstrates the potential for a new category of event that is at once in-person and virtual. ABBA’s reanimation took six years and cost £140m (US$175m), a third of which went on the high-tech London stadium. The band members spent five weeks performing on a stage in Stockholm, in front of 160 cameras operated by Industrial Light and Magic, a visual-effects company that has previously brought to life Jedi knights and Avengers.