Decca Tree
Musical milestones, both technical and artistic, are tough to pin down; once you think a date is set in stone, someone makes a discovery that re-designates your pet milestone as "asterisked," if not thrown out entirely. But the invention of the Decca Tree, a disarmingly simple device used in stereo orchestral recording and currently in Surround Sound sessions, is traceable to one man, British engineer Roy Wallace, who passed away in London at 80 on August 18.

In 1942, Wallace joined the staff of Radio and Television Engineering (or RTE) in London, run by inventor Lawrence Francis Savage. In the 1930s, Savage had worked in the BBC unit under Alan Blumlein that had developed an experimental form of stereophonic recording, a project halted by Blumlein's early death and the outbreak of World War II. In 1947, Wallace and Savage revived this stereo system utilizing some surviving equipment from the previous experiments -- two turntables running in synchronization -- and made improvements. One step forward, made in 1950, was Wallace's creation of a "head" containing three microphones; one pointed forward, and the other two angled out at 70 degrees. Successful stereo recording isn't just a matter of capturing right and left channels; there is the dreaded "mid-side" perspective or the center left and right of the stereo picture, and Wallace was the first inventor to address this issue. Along with the early "head," he also developed a three-channel mixer called the "ST1" that could convert three microphone inputs into two.

Neumann M49In November 1952, Wallace and Savage demonstrated their stereo system to Edward Lewis, head of Decca Records in the UK. Lewis was enthusiastic about stereo, not only because it seemed like "the way of the future," but also because it meant getting a leg up on his competitors, such as EMI, who proved slow to adopt the new technology. Lewis asked Wallace to join Decca's regular staff, which forced Savage out of the picture, and Wallace worked with a team headed by Arthur Haddy for another year to perfect Decca's brand of stereo -- still recording on disc since the first Ampex multi-track tape recorder did not arrive at Decca until April 1954. Wallace first brought out the "Decca Tree" at Decca's first experimental stereo session, held December 23, 1953, attaching three Neumann M49's to it and flying the device high over Mantovani's orchestra on a boom. When Arthur Haddy first saw it, he commented "It looks like a bloody Christmas tree," and that's how the Decca Tree got its name.

Mantovani All American Showcase (Sample) Mantovani: "A Kiss in the Dark" from All-American Showcase
Mantovani was certainly an appropriate choice for Decca's first stereo session; his orchestral sound was based on a stereophonic arrangement of the orchestra, impossible to catch on monophonic recordings. In time "Monty" would become the first artist to sell a million stereo LPs. However, stereo albums were not yet technically possible until 1958, with Decca the first in England to bring them out. In the intervening years, Decca continued its experimental stereo experiments with the Suisse Romande Orchestra of Ernest Ansermet, who proved an enthusiastic early proponent of stereo, and in recording a complete Ring cycle at Bayreuth in 1955. Most of these experimental recordings remained in the Decca vault until 2006, when some of them were finally issued by the UK-based re-issue label Testament. Roy Wallace continued to work at Decca until he retired when it was taken over by Polygram in 1980.

Roy Wallace did not "invent" stereo; alongside Blumlein, experimenters at Bell Labs were working towards that end in the 1930s, and researcher Patrick Feaster of Indiana University has suggested that "accidental" stereo recordings may have been made at the Chicago World's Fair as early as 1893. Nevertheless, Wallace's simple device, which looks like something you could hang your clothes out to dry on, has made a believer out of every engineer who has tried it terms of avoiding "mid-center buildup" and in maintaining an accurate balance in symphony orchestra recordings; though its inventor is now gone, the Decca Tree is still in use.

Die Walkuere
(Sample) Joseph Keilberth, Bayreuth Festival: Wagner: Die Walküre: Act 3, Scene 1 (recorded 1955)