Eddie "Lockjaw" Davis, also known as Jaws, was a self-taught originator of soul jazz. He recorded the first records that blend Hammond organ and tenor sax, with Bill Doggett at the B3, for Roost Records in May 1952. He continued to develop his blues-based, jukebox-friendly style of jazz and, in 1955, joined forces with a young organ player from Philadelphia named Shirley Scott. They recorded together for King and Prestige Records and formed a gigging band with drums and bass.

In three 1958 sessions at Rudy Van Gelder's Hackensack, New Jersey, "living room" studio, Davis and Scott recorded four seminal soul-jazz albums, the "Cookbooks." Themed around bluesy originals and spirited takes on comfortable standards, the albums featured liner notes and song titles that relate to an imagined soul kitchen, with a generous helping of kitschy references to the "simmerin'" music on the platters. Craft Recordings, the reissue label for the Concord Music Group, has collected the four "Cookbook" albums into a box set of vinyl cut from the two-track master tapes by Bernie Grundman and plated and pressed at RTI in California.

Back in the 1950s, Cesare Sanavio, then a new electronics graduate with a specialty in output transformers for tube amplifiers, began his career in radio and television, traveling to various locations outside his native Italy to apply his expertise. Eventually he settled in Paraguay and started designing tubed sound systems for public installations, teaching his son Luciano the art. A few years later, Sanavio and his family returned to Italy. There, he worked as a consultant to several hi-fi companies. Finally, in 1994, drawing on decades of accumulated knowledge of tube-amplifier design and manufacturing, and a particular focus on output transformers of the highest quality, Cesare Sanavio and his two sons, Luciano and Lorenzo, formed Mastersound.

When Cesare Sanavio died, Lorenzo and Luciano continued operations. In 2015, the company re-formed, with some new international business connections and a new CEO, Antonio Ferro.