Keystone via Getty Images, FILE The brothers' only sister, Marie Osmond, also became a singer and launched a solo career in the 1970s. Merrill Osmond also took to social media to mourn his brother ...

and their early lineup consisted of Osmond and brothers Alan, Merrill and Jay. The singer's younger siblings Donny and Jimmy would later join the group, while sister Marie launched a solo country ...

"I'm sure I speak on behalf of every one of us siblings when I state that we were fortunate to have Wayne as a brother," Donny Osmond wrote on social media. Wayne Osmond, the singer and musician ...