Wayne Osmond, a founding member of family band The Osmonds, who had a string of hits in the 1970s, has died at the age of 73.

Wayne was a singer and guitarist, and co-wrote many of their biggest hits, including Crazy Horses, Goin' Home And Let Me In.

"Wayne brought so much light, laughter, and love to everyone who knew him, especially me," wrote brother Donny. "He was the ultimate optimist and was loved by everyone."

Merrill Osmond called his late brother "a genius in his ability to write music" who was "able to capture the hearts of millions of people and bring them closer to God".

He continued: "I've never known a man that had more humility. A man with absolute no guile. An individual that was quick to forgive and had the ability to show unconditional love to everyone he ever met."

Merrill and Donny said the cause of death was a stroke.

Born in August 1951, in Ogden, Utah, Wayne was the fourth oldest of nine children and raised in a Mormon household.

As a child, he started performing in a barbershop quartet with siblings Alan, Merrill and Jay.

By 1961, the harmonising brothers were regular performers at Disneyland in California. A year later, they made their TV debut on The Andy Williams Show.

They quickly became regulars on the show, earning the nickname "one-take Osmonds" because of their flawless, tirelessly rehearsed performances.

Younger sibling Donny joined the line-up in 1963, and they began to broaden their repertoire to include clean-cut pop songs.

Their initial singles flopped but, after the success of the Jackson 5 showed that family pop could be a commercial success, MGM Records signed the band and sent them to work at the famed R&B studio Muscle Shoals.

There, they were given a song called One Bad Apple (Don't Spoil the Whole Bunch), which had originally been written for the Jacksons but was rejected by their record label.

Perky, bubbly and bright, the song topped the US singles chart for five weeks in 1971 and established the band as a chart presence, a decade after their professional debut.

For a while, the siblings generated the same sort of fevered excitement as The Beatles.

When the band flew into Heathrow Airport in 1973, 10,000 teenage fans packed the roof gardens at a nearby office block to see them arrive. Part of the balcony railing and wall collapsed amidst a crowd surge, slightly injuring 18 women.

On their departure, hundreds of fans mobbed their limousine. A reporter for the New York Times said "they were lucky to escape alive", while the Guardian said the scenes almost led to a ban on pop groups entering the UK via Heathrow.

But pop is a fickle industry, and The Osmonds' record sales started to tail off by the mid-1970s.

At the same time, Donny and Marie Osmond were offered their own TV variety show, which became a massive hit in the US and was screened by BBC One in the UK.

As a result, the band went on hiatus and ultimately dissolved in 1980, although they regularly reformed for county fairs and reunion tours over the coming decades.

Wayne Osmond suffered a number of health problems during his life. He was diagnosed with a brain tumour as a child, which resulted in cognitive problems.

In 1994, he noticed that the condition was worsening.

"I noticed I couldn't play my saxophone any more because my head would start throbbing," he later recalled. "And my knees would fall out from under me when I was on stage. This all began happening within a week."

The subsequent surgery and related cancer treatments resulted in significant hearing loss that persisted for the rest of his life. He also suffered a previous stroke in 2012.

In 2019, the musician joined his siblings Alan, Merrill and Jay for their final ever performance on TV show The Talk.

Performing in front of a screen that showed a montage of their career highlights, the original quartet performed a song called The Last Chapter, written as a thank you to their fans.

Sister Marie, who presented the show, joined them afterwards to pay tribute, saying: "I am so honoured to be your sister. I love you guys. You've worked so hard. Enjoy your retirement."

Wayne spent his retirement indulging in hobbies including fly fishing, and spending time with his family. He maintained an optimistic outlook, telling Utah newspaper Desert News that hearing loss didn't bother him.

"My favourite thing now is to take care of my yard," he said. "I turn my hearing aids off, deaf as a doorknob, tune everything out, it's really joyful."

He is survived by wife Kathlyn and five children, Amy, Steven, Gregory, Sarah and Michelle.

He is also survived by his eight siblings: Virl, Tom, Alan, Merrill, Jay, Donny, Marie and Jimmy.