In 1803 in London, he became president of the Jennerian Society, concerned with promoting vaccination to eradicate smallpox. The Jennerian ceased operations in 1809. In 1808, with government aid, the National Vaccine Establishment was founded, but Jenner felt dishonoured by the men selected to run it and resigned his directorship. Jenner became a member of the Medical and Chirurgical Society on its founding in 1805 (now the Royal Society of Medicine) and presented several papers there. Jenner was also elected a foreign honorary member of the American Academy of Arts and Sciences in 1802, and a foreign member of the Royal Swedish Academy of Sciences in 1806.
Returning to London in 1811, Jenner observed a significant number of cases of smallpox after vaccination. He found that in these cases the severity of the illness was notably diminished by previous vaccination. In 1821, he was appointed physician extraordinary to King George IV, and was also made mayor of Berkeley and justice of the peace. He continued to investigate natural history, and in 1823, the last year of his life, he presented his "Observations on the Migration of Birds" to the Royal Society.
In the United States, electronic music was being created as early as 1939, when John Cage published Imaginary Landscape, No. 1, using two variable-speed turntables, frequency recordings, muted piano, and cymbal, but no electronic means of production. Cage composed five more "Imaginary Landscapes" between 1942 and 1952 (one withdrawn), mostly for percussion ensemble, though No. 4 is for twelve radios and No. 5, written in 1952, uses 42 recordings and is to be realized as a magnetic tape. According to Otto Luening, Cage also performed a William [sic] Mix at Donaueschingen in 1954, using eight loudspeakers, three years after his alleged collaboration. Williams Mix was a success at the Donaueschingen Festival, where it made a "strong impression".
The Music for Magnetic Tape Project was formed by members of the New York School (John Cage, Earle Brown, Christian Wolff, David Tudor, and Morton Feldman), and lasted three years until 1954. Cage wrote of this collaboration: "In this social darkness, therefore, the work of Earle Brown, Morton Feldman, and Christian Wolff continues to present a brilliant light, for the reason that at the several points of notation, performance, and audition, action is provocative."
Cage completed Williams Mix in 1953 while working with the Music for Magnetic Tape Project. The group had no permanent facility, and had to rely on borrowed time in commercial sound studios, including the studio of Louis and Bebe Barron.