Roberto Gerhard was a pioneer of electronic music in England creating over twenty substantial concert, theatre and radio works from 1954. However, for various political, cultural and personal reasons Gerhard’s electronic music has not been published or widely disseminated. Gerhard’s electronic music is one of the richest repositories for understanding the development of the composer’s late compositional technique as well as the early development of electronic music in the UK. This article presents the summation of a decade of work produced alongside researchers Dr Carlos Duque and Dr Gregorio Karman on the Roberto Gerhard archive held at the Cambridge University Library (CUL), England. Gerhard’s archive at the CUL contains his books, letters, manuscripts, notebooks and most pertinent to this article, over 600 magnetic tapes. Whilst some of these tapes contain recordings of works by other composers, most pertain to Gerhard’s instrumental and electronic compositions. The article covers Gerhard’s working methods, his studio, his relationship to the BBC Radiophonic Workshop. The article draws on previous publications by the author, notably: In Search of a ‘Third Way’ and Claustrophilia: A Musical Gift from Gerhard to John Cage. In addition, the article provides a newly revised list of the composer’s extant electronic works based on research in the tape archive.