In this paper, I draw on seminal literature from new media researchers to frame the broader implications that user-generated content (UGC), YouTube, and participatory culture have for music learning and teaching in online communities; to illustrate, I use examples from two contrasting online music communities, the Online Academy of Irish Traditional Music (OAIM, www.owim.ie) and the Banjo Hangout (www.banjohangout.org). The different ways people employ UGC such as YouTube videos for music learning and teaching in online participatory communities has significant implications for music learning and teaching in on and offline contexts.