At more than 50 foot tall it was so large that it had to be transported in 18 sections and assembled on site by a team of 15 workmen.
Almost one million multi-coloured lights make up the singing tree, which has more than six miles of lighting cable, 216 twinkling star flashes, over 3,000 bauble decorations and 24 huge snowflakes with a giant illuminated star on top.
Longleat's Steve Mytton told Aol Travel: 'It's been an incredible job. It took six months to develop and build and four days for the guys to put it together on site.
'With so many lights, so much cable and decorations to check it has been a massive undertaking but to see the tree finally in place and working is amazing.'
The tree will be on display from now until 2 January as part of the attraction's 'Christmas at Longleat'.
The unveiling of the tree, which also dances to festive tunes, is one of many Christmas attractions opening across Britain that signal the real start of the festive period.
In London, Olympic champion Jayne Torvill took to the ice rink at Somerset House, which will open to the public on Tuesday 22 November and run until January, and has been dubbed the capital's 'most glamorous ice rink'.
There'll be concerts, DJ nights, and skate shows, as well as the simple opportunity to just pull on your skates and have a go.
An ice rink over at the Tower of London has also been keeping visitors busy since the 19 November.
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