This fine box offers critically important recovered documents from the British ensemble, Intermodulations, one of a handful of hybrid groups formed in the 1960s to explore new ways of making music in the art tradition using conventional instruments as well as performer-controlled electronic modification and pure electronics (other, better documented, exemplars include MEV, AMM, Stockhausen’s ensemble, Sonic Arts Union and Gruppo di Improvvisazione Nuova Consonanza). Electrification and a quest both for new sounds and new ways of organising them, burned strong in this period and Intermodulations played an important but, until now, undocumented part. This collection redresses that lack. Composers featured include Karlheinz Stockhausen, Terry Riley, Tim Souster, Cornelius Cardew and Roger Smalley. There are also several credited to the ensemble itself, which was formed by Souster and Smalley with students Andrew Powell and Robin Thompson (both of whom went on to unusual and glittering careers). Also featured are Peter Brittan (who replaced Powell), Mike Ratledge, Simon Emmerson and Joshua Rifkin, The recordings themselves are from private and radio archives and the accompanying booklet is a model of its kind, fascinating, full of surprises and historically important; nicely designed and with excellent photographs. Notable are Terry Riley’s pieces, the first offering a curious, but instructive, mix that features a very upfront saxophone with the keyboards washing around in the background; the second is a tidal wave of roiling chaos, and the third the famous performance, with Mike Ratledge, of Keyboard Studies at the 1970 BBC Proms. Stockhausen is represented by 5 pieces, including Wellen, written in Ceylon with percussion and piano to the fore; nicely recorded and performed. The Cardew piece (with Joshua Rifkin) is interestingly minimal while Roger Smalley’s Melody Study is a (close to) precision roller coaster derived from a simple melody and highly productive generative rules. Special mention though to Tim Souster – an important figure, much under-represented in the histories and with almost no extant recordings – who offers three compositions here: Zorna (also performed at the 1970 proms), for soprano saxophone, tape delay and three drummers, Chinese Whispers  -------- and, the side-length epic, World Music – an impressive fully-honed composition mixing purely electronic passages with purely instrumental passages, bringing both together at the end. Experimental and highly original, this is probably worth the price of the box on its own. The original being lost, it was reconstructed for this box from radio rehearsal tapes and the Souster’s original electronic interpolations. Taken together, this release captures capture perfectly the aesthetic and spirit of creative investigation that marked the time.