El Sistema – “the system” – is a music education phenomenon. Since its inception 40 years ago, over a million Venezuelan children from many different socio-economic backgrounds have participated in its mission of “social change through music”. Ironically, the essence of The System is that it is a non-system – at least insofar as there are no rigid rules or guidelines. Instead, it is based on a tried and tested philosophy that practitioners need to mold and adapt as best serves their communities. While the flexible nature of El Sistema is central to its original success and its worldwide adaptability, the lack of any clear-cut system can be daunting for those trying to understand, implement or develop a philosophy that Sir Simon Rattle has called “the most important thing happening in the world in classical music." El Sistema therefore offers practical information for those seeking knowledge, inspiration, or guidance for adapting El Sistema to widely divergent socio-economic settings, particularly within the USA. Designed as a collection of essays, it explores the voices and experiences of teachers, leaders, parents, and experts from related fields with the hope of inspiring actions, both large and small, to advance social change through music.