Green also popped the question to longtime girlfriend Shani James while making music.
"It was just a typical night at the studio, but then again, not so typical cause I did something extra special, out of the ordinary," he told People. "I went and purchased a ring that we had seen together, maybe four or five months or so prior. I went back and purchased the ring, and I just kind of had it stashed away in some old equipment. And I said, 'Will you reach in there and grab something for me?'"
See Cee Lo through the years:
CeeLo Green - updated 9/9/14
CeeLo Green has been secretly engaged for a year
Singer CeeLo Green, whose real name is Thomas DeCarlo Callaway, attends a hearing at the Los Angeles Superior Court House on August 29, 2014 in Los Angeles, California. Green pleaded no contest to a felony charge of furnishing ecstasy and was sentenced to three years of probation. The charge stems from a 2012 incident where he was accused of slipping ecstasy into a woman's drink. (Photo by David Buchan/Getty Images)
Ceelo Green performs during the Beer Fest on August 13, 2014 in Belgrade, Serbia. (Photo by Srdjan Stevanovic/Getty Images)
CeeLo Green performs before an outdoor NHL hockey game between the New York Rangers and New York Islanders at Yankee Stadium in New York, Wednesday, Jan. 29, 2014. He flashed a middle finger at the crowd as he left the stage after being incessantly booed throughout the performance.(Photo by Andy Marlin/NHLI via Getty Images)
THE VOICE -- 'Live Show' Episode 519A -- Pictured: CeeLo Green -- (Photo by: Trae Patton/NBC/NBCU Photo Bank via Getty Images)
Pimlico Race Course, Baltimore, MD The Virgin Festival Singer for Gnarls Barkley, Cee-Lo Green, takes the stage at the Virgin Festival. (Photo by Tracy A. Woodward/The Washington Post/Getty Images)
CHULA VISTA, CA - JUNE 07: Singer/songwriter CeeLo Green performs on stage in support of Lionel Richie's 'All The Hits All Night Long' tour at Sleep Train Amphitheatre on June 7, 2014 in Chula Vista, California. (Photo by Daniel Knighton/Getty Images,)
LAS VEGAS, NV - JUNE 06: Recording artist CeeLo Green performs as he opens for Lionel Richie at the Mandalay Bay Events Center on June 6, 2014 in Las Vegas, Nevada. (Photo by Ethan Miller/Getty Images)
ANAHEIM, CA - JUNE 03: CeeLo Green performs at Lionel Richie's 'All The Hits All Night Long' Tour With CeeLo Green - Anaheim, CA at Honda Center on June 3, 2014 in Anaheim, California. (Photo by Gabriel Olsen/FilmMagic)
VANCOUVER, BC - MAY 29: Recording artist CeeLo Green opens for Lionel Richie 'All The Hits All Night Long' tour at Pepsi Live at Rogers Arena on May 29, 2014 in Vancouver, Canada. (Photo by Andrew Chin/FilmMagic)
THE VOICE -- 'Live Show' Episode 517A -- Pictured: (l-r) Adam Levine, CeeLo Green -- (Photo by: Trae Patton/NBC/NBCU Photo Bank via Getty Images)
CENTURY CITY, CA - MAY 02: Recording artist CeeLo Green performs onstage at the 21st annual Race to Erase MS at the Hyatt Regency Century Plaza on May 2, 2014 in Century City, California. (Photo by Michael Buckner/Getty Images for Race to Erase MS)
AUSTIN, TX - MARCH 15: CeeLo Green performs as part of Rachel Ray's Feedback Party at Stubbs Bar-B-Que on March 15, 2014 in Austin, Texas. (Photo by Tim Mosenfelder/Getty Images)
THE VOICE -- 'Live Show' Episode 516B -- Pictured: (l-r) CeeLo Green, Christina Aguilera -- (Photo by: Trae Patton/NBC/NBCU Photo Bank via Getty Images)
ATLANTA, GA - SEPTEMBER 29: Little Richard and CeeLo Green chat backstage at 'The Legacy Lounge' A conversation with CeeLo Green and his inspiration at W Atlanta - Downtown on September 29, 2013 in Atlanta, Georgia. (Photo by Rick Diamond/WireImage for NARAS)
TODAY -- Pictured: (l-r) CeeLo Green and James Franco appear on NBC News' 'Today' show -- (Photo by: Peter Kramer/NBC/NBC NewsWire via Getty Images)
The couple has been keeping their engagement on the mum.
"Truth be told, it's not something we want to promote," said the "Forget You" singer. "We're a collective power together because our private life is sacred."
Former Voice coach Green has been heavily scrutinized since facing a felony drug charge and posting some controversial tweets.
"I appreciate her openness and willingness to love unconditionally," Green told Peopleof his fiancee. "She's been so sweet to me through a number of different trials that come to test the resilience of a union to deem whether it's worthy or not, whether it's durable or strong enough. "