Run in the northern suburbs by Aaron Curnow, the music aficionado would have been happy to celebrate locally but is thrilled for more extravagant soirees. 

"I was totally happy celebrating the labels 20th at my local bowling club, with bands and barefoot bowls," Spunk founder Aaron Curnow said.

"Like most things in life, particularly in the creative arts world, you have a short run.

"To also be doing it at the Sydney Opera House and for Vivid and with the Middle East, I've really got to pinch myself. It's a humbling experience."

Headlining the two shows is Townsville indie/folk rockers the Middle East who have decided to reform for the one-off performances - a personal favour to their record label.

They'll play alongside label-mates The Ocean Party (before they disband forever), Emma Russack, Machine Translations, Jack Ladder and Holly Throsby.

Spunk spawned from a fanzine Curnow created with the late Kieran Dyson, which evolved into touring bands and then creating the label in 1999.

"I started touring a couple of bands and we met lots of people with the fanzine so then I just started asking people if I could release their records," he said.

The first release was Bonnie "Prince" Billy's I See A Darkness album.

Over two decades Spunk has released 550 albums from a plethora of artists such as Arcade Fire, Bat For Lashes, Antony & the Johnsons, Sufjan Stevens, Belle and Sebastian, Mogwai, Joanna Newsom, Four Tet and Bill Callahan.

Spunk will be also reissue some of the classic domestic releases on its label to commemorate the milestone including albums from Jack Ladder, Holly Throsby, Firekites, the Middle East, Wagons and Machine Translations.

To purchase tickets for the 20^th birthday shows, visit: www.sydneyoperahouse.com