Hal Rammel became involved in Chicago’s experimental jazz scene in the seventies and eighties. He has performed and recorded at the Experimental Sound Studio from its inception into the 2000s. The Penumbra Music Collection fills two boxes and includes both audio recordings and documents related to the Penumbra Music label. The material spans the period from Penumbra’s creation in 1994 to 2015. The audio material contains commercial, beta, and live recordings of the label. The documents are largely administrative, but also include magazine clippings, event announcements, and other ephemera of the label’s work.