This article discusses the use of an accessible visual notation system that represents the melodic component of an electronic music composition in acid house music, based on programming the Roland TB-303 bassline synthesiser’s sequencer. This notation system can be used for sharing, composition, collaboration and archival purposes. This system is called an acid pattern. The article analyses a variety of different approaches to communicate acid patterns. It examines the requirements and visual elements used and how they relate directly to the functionality of the Roland TB-303’s sequencer. Through content analysis of images, text and audio data gathered from various music community websites this article furthers the understanding of how the practices and cultures of acid house music composition, notation and archiving are shared online and how they, enabled by web-based technologies, can build communities. This article suggests important possibilities for communities of practice-based around a shared cultural identity, accessible notation systems, and the creation and recreation of music in both online and offline contexts.