The pair's escape caused panic among the staff when they couldn't be found with the nursing home alerting police of their disappearance.
After an extensive search, the pensioners were found at 3am in the crowd at Wacken Open Air music festival in Germany.
According to local reports, the ageing metalheads were reluctant to leave the party so police had to send them home in a taxi escorted by a police car.
A local police officer Merle Neufeld said: "Both were disoriented and apathetic."
The 2018 concert marked the Wacken Festival's 29th year, which saw a sold-out crowd of more than 75,000 people.
This year's festival was headlined by the Red Hot Chilli Peppers, Judas Priest, Danzig and Hatebreed, with performances by Vince Neil, Dokken, Tremonti, Cannibal Corpse and Fozzy, among many others.
Wacken Open Air is famous for its muddy grounds, however, this year's heatwave caused concern for fire and dust risks.
The festival took place from August 1 to 4.
From now on it looks like these two pensioners will have to keep their headbanging antics inside the nursing home.