Tate bosses have apologised "unreservedly" for a ticketing disaster this week which left many fans of German electronic group Kraftwerk unable to see the band after the gallery's website could not cope with demand.
It created further frustration when the gallery then began selling tickets to visitors who turned up to Tate Modern - which will host the show - to buy them in person, which had not been part of the original plan.
Most of the tickets ended up being sold by phone, leading to lengthy waits which left many fans disappointed.
Kraftwerk are due to play a rare series of shows early next year, performing classic albums in full.
The Tate said it had expected its website to cope with the volume of traffic but admitted that it had been "overwhelmed by the phenomenal number of people attempting to access it simultaneously".
In a message on its website the gallery acknowledged people had a "difficult time", adding: "We apologise unreservedly for that."
It went on: "We expected to sell most of the tickets online before the galleries opened and did not anticipate selling tickets in the gallery.
"Some customers came to Tate Modern and we made the late decision to sell tickets to them to avoid their disappointment.
"We are sorry that this was not communicated as an official route to buy tickets and subsequently led to more frustration from other customers trying to buy tickets online and by telephone."
The shows by the electronic music pioneers - in which they will perform tracks from albums such as The Man-Machine and Trans Europe Express - have now sold out.