The book’s overarching aim is to examine the city formed by urban music cultures, often in stark opposition to the commodified image of the city crafted by urban planners and associated urban stakeholders. For more than a century, Los Angeles (L.A.) has stimulated the imaginations of all sorts of artists and has been primary material in countless movies, TV series, novels, poetries, video games, and songs. This flow of cultural production constantly reconfigures urban imaginaries associated to L.A. This chapter delineates a methodological approach to studying underground music cultures in L.A., where the analysis of urban media in relation to music and urban spaces is connected to existing urban theory on L.A. It discusses the power of music in shaping our perception of the city and explores the relationship between music cultures and L.A., which are co-constitutive of a specific urban imaginary. This book covers the multiple dimensions of L.A.’s underground music cultures: song lyrics, album covers, the association of music and image (music videos) and their aesthetics, the imaginary soundscapes associated with urban digital worlds based on L.A., as well as the subjective city experiences by both artists and the underground music audience.