DJs Friction and another act Dimension are no longer in the line-up. Festival organisers said it was due to the impact of COVID-19.
The sold-out Wanaka music festival started today and will be one of New Zealand's biggest destinations for New Year celebrations.
There were also other losses to the line-up as a result of problems caused by the pandemic.
Sampa the Great was not able to leave South Africa as all flights were cancelled, and Harriet Jaxxon, Lenzman, CC:Disco!, and Bradley Zero were not able to get MIQ rooms to enter New Zealand.
Festival director Alex Turnbull said Rhythm and Alps sold out yesterday morning.
Turnbull said people were encouraged to upload their COVID-19 vaccine passes before arriving, and staff would follow procedures closely.
"So you know, it'd be pretty hard to be fraudulent, and if someone doesn't have their conditions of entry sorted, that's the way it's gotta be."
Sister festival Rhythm and Vines and popular festival Northern Bass have been postponed until 2022 because of Covid-19.