Mark Hudson has achieved a lot in his lifetime. He was one-third 1970s sensation the Hudson Brothers and co-writer of Aerosmith’s Grammy-winning smash “Livin’ on the Edge” and Celine Dion’s “The Reason.” He recorded some of John Lennon’s solo hits off 1971’s Imagine with Ozzy Osbourne and produced albums for Ringo Starr and Hanson, among countless credentials as a seasoned musician and hitmaker. But the uncle to actress Kate Hudson, who serendipitously starred in 2000’s iconic film “Almost Famous” about a gutsy 1970s rock band whose mission was to use their spunk as soulful musicians to influence a culture, finds himself in a similar position in the present day. His purpose? Not to become famous or perform for the ecstasy of crooning the songs of that tender era that he holds so dear, but to introduce Generations Z and Alpha to the epoch that reared some of the greatest musicians in music history. Namely, the mesmerizing harmonizing abilities of David Crosby, Stephen Stills, Graham Nash and Neil Young— the folk supergroup baby boomers, Gen X and Y know well as Crosby, Stills, Nash and Young.