Each year since, Warmbrand has presented about four or five concerts by a wide variety of folk acts from all over the world. The one constant each year has been a gig by King, who usually attracts a full house.
Over the years, Warmbrand and King became fast friends and respected colleagues. They learn, perform and critique each other's songs, and meet up at conferences.
So it was a given that Warmbrand and Itzaboutime Productions would celebrate their 25th anniversary with an appearance by King. But Warmbrand and King, wanting to give a little back to Tucson fans who have supported them for a quarter of a century, decided to make this Friday night's concert a free one.
Warmbrand remembers that first King concert at the west campus of Pima Community College, in 1979.
"It was just this plain room with folding chairs on the floor, no risers. I remember Charlie singing a song I'd never heard before called 'Everybody Wants Their Own,'" Warmbrand said in an interview last week.
During the next couple of years, King's concerts moved to venues on and around the University of Arizona campus. The series eventually settled, with the exceptions of brief forays to other locations, at the Unitarian Universalist Church.
Which is where King will perform this week. Karen Brandow, King's partner in life and music, will join him on stage, as she has done for the last four years. Of Brandow, Warmbrand said, "She has a voice as clear as a bell. She stops the show every year with her solo songs. She plays a guitar in the classical style, that she built herself, which has incredible sound."
Warmbrand met King during the mid-1970s. Warmbrand was a traveling song collector, learning and passing along folk tunes. King impressed Warmbrand with his songwriting, his integrity and his ability to explore pointed political and social subjects with a dollop of humor.
"Charlie's class consciousness was always a strong point. He has a very natural disdain for hypocrisy and airs, a real love for the common person who does the right thing," Warmbrand said.
"His character is of this playful, free-flowing guy with a twinkle in his eye, and a nice bite to his lyrics. His ability to hit these big subjects without making you feel like he's scolding you is part of his charm, I think. What does he say? That it's all about ordinary people doing extraordinary things."
King oft has sung of such people in tunes such as "Joe Hill," "Two Good Arms," "U.S. Steel," "Our Life Is More Than Our Work," "What If the Russians Don't Come?" and "Are You Now or Have You Ever Been...?"
King's Itzaboutime concerts also have provided fund-raising opportunities for activist organizations throughout the city--the Primavera Foundation homeless shelter, Witness for Peace Sanctity of Life (SOLPAE), People Against Execution, BorderLinks, etc. The list goes on.
"And when one group doesn't seem strong enough or eager enough to sell the hall, I've split the hall up so different groups can benefit from the event," Warmbrand says. "This year is the first departure where we aren't selling the tickets. We've giving them away."
King's concerts, and Itzaboutime shows in general, have not only provided food for the soul. Accompanying dinners have become a tradition.
This year's meal--to be supplied by Mexican restaurant La Indita--is, like the concert, free. But if you haven't made reservations, you're out of luck.
"At this point, we have no more room for the dinner," Warmbrand said last week. "The concert hall can take another 100 people."
Of course, King's shows haven't been Itzaboutime's only productions.
Warmbrand has presented more than 100 events over the years, including concerts by Yothu Yindi, Malathini and the Mahotella Queens, Sweet Honey in the Rock, Guardabarranco, Peggy Seeger, Ewan MacColl, Judy Small, Floyd Westerman, Pete Seeger, Ronnie Gilbert, Holly Near, Joan Baez, Ruth Pelham and Si Kahn.
Warmbrand was delighted to work with several Sanctuary benefit events over the years, including a massive rock concert in the middle 1980s featuring Jackson Browne, Don Henley, Stevie Nicks, Bonnie Raitt and Stevie Ray Vaughan in the UA's McKale Center.
Itzaboutime also has delved into presenting the premiers of theater (the San Francisco Mime Troupe, Ladies Again Women) and film events (Incident at Oglala, Coverup: Behind the Iran-Contra Affair).
Perhaps closest to Warmbrand's heart are the King concerts, and not simply because King's performances in Tucson reportedly draw his largest numbers of fans outside of St. Louis.
"The idea that we have remained friends over the years and we have kept this relationship going has been really wonderful for me.
"I miss seeing him more often than I do. But we get to sing together once a year at the end of his concert. He calls me up, and we sing together a song that maybe we rehearsed in the intermission, if at all. It's real ragged and raw. He's always been very generous about that. That's always a joy for me."