<human>: Sir George Henry Martin  (3 January 1926 - 8 March 2016) was an English record producer, arranger, composer, conductor, audio engineer, and musician. He was referred to as the "Fifth Beatle", including by Paul McCartney, in reference to his extensive involvement on each of the Beatles' original albums. Martin produced 30 number-one hit singles in the United Kingdom and 23 number-one hits in the United States. Martin produced comedy and novelty records in the early 1950s, working with Peter Sellers, Spike Milligan, and Bernard Cribbins, among others.

Following his graduation, he worked for the BBC's classical music department, then joined EMI in 1950 as an assistant to Oscar Preuss, the head of EMI's Parlophone Records from 1950 to 1955. Although having been regarded by EMI as a vital German imprint in the past, it was then not taken seriously and only used for EMI's insignificant acts. After taking over Parlophone, as head of artists and repertoire, when Preuss retired in 1955, Martin recorded classical and Baroque music, original cast recordings, and regional music from around Britain and Ireland.  Martin also produced numerous comedy and novelty records. His first hit for Parlophone was the "Mock Mozart" single by Peter Ustinov with Antony Hopkins - a record reluctantly released in 1952 by EMI, only after Preuss insisted they give his young assistant, Martin, a chance. Later that decade Martin worked with Peter Sellers on two very popular comedy LPs. One was released on 10 format and called The Best Of Sellers, the second was released in 1957, being called Songs for Swinging Sellers (a spoof on Frank Sinatra's LP Songs for Swingin' Lovers!). As he had worked with Sellers, he also came to know Spike Milligan, with whom he became a firm friend, and best man at Milligan's second marriage: "I loved The Goon Show, and issued an album of it on my label Parlophone, which is how I got to know Spike." The album was Bridge on the River Wye. It was a spoof of the film The Bridge on the River Kwai, being based on the 1957 Goon Show episode "An African Incident." It was intended to have the same name as the film, but shortly before its release, the film company threatened legal action if the name was used. Martin edited out the 'K' every time the word Kwai was spoken, with Bridge on the River Wye being the result. The River Wye is a river that runs through England and Wales. The album featured Milligan, Sellers, Jonathan Miller, and Peter Cook, playing various characters.  Other comedians Martin worked with included Bernard Cribbins, Charlie Drake, Terry Scott, Bruce Forsyth, Michael Bentine, Dudley Moore, Flanders and Swann, Lance Percival, Joan Sims, Bill Oddie, and The Alberts. Martin worked with both Jim Dale and the Vipers Skiffle Group, with whom he had a number of hits. In early 1962, under the pseudonym "Ray Cathode," Martin released an early electronic dance single, "Time Beat" - recorded at the BBC Radiophonic Workshop. As Martin wanted to add rock and roll to Parlophone's repertoire, he struggled to find a "fireproof" hit-making pop artist or group.  As a producer, Martin recorded the two-man show featuring Michael Flanders and Donald Swann, At the Drop of a Hat, which sold steadily for twenty-five years, although Martin's breakthrough as a producer came with the Beyond the Fringe show cast album, which starred Peter Cook, Dudley Moore, Alan Bennett, and Jonathan Miller, and he would also produce the accompanying soundtrack album for David Frost's satirical BBC TV show That Was the Week That Was in 1963. Martin's work transformed the profile of Parlophone from a "sad little company" to a very profitable business. CANNOTANSWER

Using a quote from the above article, answer the following question: Who was the head?
<bot>: when Preuss retired in 1955,