Klub K4 is Ljubljana's only nightclub specialised in contemporary, non-commercial clubbing music, regularly inviting prominent foreign DJs and producers from the fields of drum'n'bass, techno, house, psy trance, nu rave and other styles. This programme is augmented by special evenings such as "Hočmo nazaj dinozavre" (We want the dinosaurs back), dedicated to styles such as old school hip hop, happy hardcore, eurodance or skate punk; "K4 Roza", where everything from Eurovision nights to the "Next Best Drag Queen" competition can take place; the "K::RAP" hip hop nights; and special features like DJ workshops and various mid-week student events.
Some of the crews organising events at K4 are Synaptic and DrumWise (both of them active here for about 15 years), the 1605 Music Therapy (a department of a techno record label founded by UMEK), and several others.
Since the club has gotten new management in 2015, it has hosted such acts as Martin Buttrich (DE), Johannes Heil (DE), London Elektricity (UK), Mike Servito (US), Jus-Ed (US), DJ Hito (JP), Fumiya Tanaka (JP), the hip hop crew High 5 (HR), Valentino Kanzyani, Jimmy Barka Experience, Your Gay Thoughts, etc.
Unofficially run by ŠKUC since the mid-1980s, K4 was formally established in 1989 in the basement under the former K6/4 Institute. A home for underground music and sub-cultural movements, the club has always had a stylistically diverse programme. Initially focused on hardcore, punk, grunge, alternative rock, hip hop and techno, it hosted the likes of Henry Rollins, Jon Spencer Blues Explosion, Asian Dub Foundation and Atari Teenage Riot. It was one of the first venues to introduce techno parties, it used to hold rap free-style battles (even organising a state competition), and was the venue of choice by numerous producers, among them the Druga godba Festival.
In 2001, with the so-called Restart season, the club almost exclusively focused on electronic music. Open for several nights per week, it hosted forward-thinking artists from the fields of techno, drum'n'bass, psytrance, IDM, experimental electronica and beyond. Functioning as an open platform for new, unconventional Slovenian musical talents, it literally had dozens of crews co-creating its programme (among them were RDYO Djs, ŠKUC Buba Booking and Promotion, Don't Make New People, and Sindikat).
A branch of the K6/4 Institute (now called the Kersnikova Institute), the club was financed and owned by the Student Organisation in Ljubljana (ŠOU), which for various reasons and for the first time in its history closed it down in March 2013. This and the new, more commercially oriented programme that soon followed provoked immense disapproval from the public, leading to the boycott by many visible protagonists of the clubbing scene. A reshaping of the musical concept and revival of the long-running collaboration with several crews brought the club back to life.
In 2014, the Zavod Štirka (Štirka Institute) began running the club until May 2015, when once again the club announced a temporary break in its activities. In September 2015, the private company Zmešaj si took over running the club. Toning down its experimental dimension, it nevertheless retained its main musical orientation.
In the past, every event in K4 had a specially designed flyer. Among the notable artist names found on them include: DJ Krush, DJ Marky, Stamina MC, Marcus Intalex, Ellen Alien, Kenny Larkin, Stanton Warriors, Bonobo, Roni Size, Goldie, Mouse on Mars, Kid 606, Josh Wink, Jazzanova, Derrick May, Richie Hawtin, Magda, Swayzak, Freddy Fresh, Eat Static, Oscar Mulero, Dan Deacon, Sutekh, Mike Shannon, Penta, Black Sun Empire, Legowelt, Emptyset, Alexander Kowalski, Surgeon, Terry Francis, Andreya Triana, Oneohtrix Point Never, Disciplina Kičme, etc.