The Grammy-winning star, whose hits included Clean Up Woman and Tonight Is The Night, had been battling cancer.
A powerful, soulful vocalist, she was one of the first singers to use the "whistle register", later utilised by Mariah Carey and Ariana Grande.
As a writer and producer, she also created hits for artists including Bob Marley, Gloria Estefan and Joss Stone.
"We mourn the loss of this beautiful soul," wrote Khan on her Instagram page. "I will miss her so."
"I loved being around Ms Betty Wright," added Legend. "She was always so loving and giving to younger artists. Always engaged, always relevant. She will be missed."
Rapper Snoop Dogg thanked Wright for the "fellowship, mentoring and prayers and blessings" she shared with him.
"I know God is pleased with your work. Tonight is the night u get to heavens gates."
Gold disc at 18
Born Bessie Regina Norris in 1953, Wright began her singing career at the age of two as a member of her family's gospel group, Echoes of Joy.
She released her first solo album, 1967's My First Time Around, when she was just 14 years old. The record delivered her first hit, Girls Can't Do What the Guys Do, a scathing critique of sexual inequality, which was later sampled by Beyonce on the track Upgrade U.
It reached number 33 on the US charts, but Wright had to turn down an appearance on TV show American Bandstand when her principal refused to give her the day off school.
Her biggest hit came in 1971 with Clean Up Woman, notable for its funky guitar riff and boisterous vocals.
It reached number six on the pop charts and sold more than one million copies, earning Wright her first gold disc just days after she turned 18.
Further hits came with Tonight Is the Night and Where Is the Love, which earned her a Grammy for best R&B song in 1975.
Wright began mentoring other musicians when she was still a teenager, helping local singers George and Gwen McRae win recording contracts. Both of them went on to score top 10 hits.
Later, she acted as a vocal coach for Jennifer Lopez and co-produced Joss Stone's debut album The Soul Sessions.
"I believe in legacy and I believe in making the radio sound better," Wright told NPR in 2011. "If I gotta listen to it, I want it to sound good.
"So I'm tired of people disturbing the peace, getting on the radio and sounding a hot mess. If I can tell what the note really is, why let them go to the note they think it is? I've got that mama vibe. I don't look at it with an ego."
A career lull in the early 1980s prompted Wright to start her own label in 1985. She made history three years later when she became the first woman to have a gold record on her own label, with the album Mother Wit and the comeback hit No Pain (No Gain).