Spiral Tribe is an arts collective and free party sound system formed in 1990. It organised free parties, festivals and raves in the UK and later Europe in the 1990s. Spiral Tribe was involved in the Castlemorton Common Festival and members have released music on labels such as Network 23 and Big Life Records. The sound system combined pagan beliefs with New Age traveller culture and rave to form teknivals. After a hiatus, the collective reformed as SP23 in 2011 and continues to organise events. Early history Spiral Tribe formed as a sound system in 1990, organising free parties in the UK. Between 1990 and 1992, the collective organised or were involved in over 30 free parties, raves, and festivals in indoor and outdoor locations. The three founding members of Spiral Tribe/SP23 were Mark Harrison, Debbie Griffith and Simone Feeney. According to Harrison, the name Spiral Tribe came to him when he was at work, staring at a poster of the interconnecting spirals in an ammonite shell. The number 23, which is associated with Spiral Tribe, was introduced by Harrison. Despite allusions to the number having been used by Psychic TV and Robert Anton Wilson, he stated that it "had nothing to do with any pre-existing individual, group or subculture". Selected parties On New Year's Eve 1991, Spiral Tribe held a rave at the then derelict Roundhouse venue in Camden, London, which lasted for a week. The building had previously used for an All Night Rave in the 1960s. Spiral Tribe organised a warehouse rave in Acton Lane, west London on 19 April 1992 (Easter Sunday). The Metropolitan Police decided to shut down the party and since the doors were barricaded, the Territorial Support Group drove a JCB through a wall to enter the party. In May 1992, the free party circuit moved up a gear and attendances increased heavily. At the beginning of the month, Spiral Tribe joined DiY Sound System and Circus Warp at Lechlade, Gloucestershire. This would reach its peak by the end of May with the Castlemorton Common Festival which became a huge party as an unintended consequence of the police preventing New Age travellers heading for the annual Avon Free Festival. Thirteen members of Spiral Tribe were arrested immediately after the event and subsequently charged with public order offences. Their trial became one of the longest-running and most expensive cases in British legal history, lasting