WELLINGTON, Sept. 26 (Xinhua) -- New Zealand computer experts said on Monday that they had restored the earliest known recording of computer-generated music, more than 65 years after it was first made.
The two-minute recording, featuring the tunes "God Save the King," "Baa Baa Black Sheep" and the Glenn Miller hit "In the Mood", was made in 1951 in the laboratory of pioneering British computer scientist Alan Turing (1912-1954), said University of Canterbury researchers.
The British Broadcasting Corporation (BBC) used a portable acetate disc cutter to capture the three melodies played by a gigantic "primeval computer" computer filled much of the ground floor of Turing's Computing Machine Laboratory, said Prof. Jack Copeland and composer Jason Long.
"Today all that remains of the recording session is a 12-inch single-sided acetate disc, cut by the BBC's technician while the computer played. The computer itself was scrapped long ago, so the archived recording is our only window on that historic soundscape," Copeland said in a statement.
The pair were disappointed to discover that the frequencies in the recording were not accurate, giving only a rough impression of how the computer sounded.
"But, with some electronic detective work, it proved possible to restore the recording, with the result that the true sound of this ancestral computer can be heard once again, for the first time in more than half a century," he said.
The researchers were able to calculate exactly how much the recording had to be speeded up in order to reproduce the original sound.
"As well as increasing the speed, and so altering the frequencies, we also filtered out extraneous noise from the recording and using pitch-correction software we removed the effects of a troublesome wobble in the speed of the recording," said Copeland.
"It was a beautiful moment when we first heard the true sound of Turing's computer."
