If you have ever wondered how to explain what Oppikoppi is to your grandma or grandpa, you no longer have to - they can now tag along free of charge. The invitation is open to pensioners over the age of 65.To add to the fun, the special guests will also get a free tequila shot - although we advise that they do not mix it with their arthritis meds.Organiser Carel Hoffman said yesterday that the invitation was part of their "Unyoung taken to the Unsea" initiative and came about during a brainstorming session."Each year we try to invite people who would normally not come," said Hoffman."Oppikoppi is a super-friendly environment and we think it will be fun."[Pensioners] can spend the weekend there and enjoy what the festival has to offer. We will bring them back feeling younger."But he warned: "No Zimmer frames in the mosh pit", saying the walking aid would give pensioners an "unfair advantage".The festival is held annually at the Oppikoppi farm near Northam in Limpopo.Initially catering for 400 people, it now boasts seven fixed stages and roughly 160 acts that cater for 20 000 music-lovers. Hoffman said re-invention was "vital" to the festival as "we have had to keep in touch with what is young and relevant".The Oppikoppi invitation comes as an 82-year-old left judges on America's Got Talent gobsmacked when he showed that heavy metal does not have an age limit.John Hetlinger, a retired Navy pilot from Broomfield, Colorado, showed off his pipes with a surprising performance of Drowning Pool's Bodies.If your ou toppie or tannie meets the criteria, and is down for a rocking weekend, register their names at info@oppikoppi.co.za. Make sure they bring their IDs along...