Charles Mingus Jr. (April 22, 1922 - January 5, 1979) was an American jazz double bassist, pianist, composer and bandleader. His compositions retained the hot and soulful feel of hard bop, drawing heavily from black gospel music and blues, while sometimes containing elements of Third Stream, free jazz, and classical music. He once cited Duke Ellington and church as his main influences. Mingus espoused collective improvisation, similar to the old New Orleans jazz parades, paying particular attention to how each band member interacted with the group as a whole.

In 1952 Mingus co-founded Debut Records with Max Roach so he could conduct his recording career as he saw fit. The name originated from his desire to document unrecorded young musicians. Despite this, the best-known recording the company issued was of the most prominent figures in bebop. On May 15, 1953, Mingus joined Dizzy Gillespie, Parker, Bud Powell, and Roach for a concert at Massey Hall in Toronto, which is the last recorded documentation of Gillespie and Parker playing together. After the event, Mingus chose to overdub his barely audible bass part back in New York; the original version was issued later. The two 10" albums of the Massey Hall concert (one featured the trio of Powell, Mingus and Roach) were among Debut Records' earliest releases. Mingus may have objected to the way the major record companies treated musicians, but Gillespie once commented that he did not receive any royalties "for years and years" for his Massey Hall appearance. The records, however, are often regarded as among the finest live jazz recordings.  One story has it that Mingus was involved in a notorious incident while playing a 1955 club date billed as a "reunion" with Parker, Powell, and Roach. Powell, who suffered from alcoholism and mental illness (possibly exacerbated by a severe police beating and electroshock treatments), had to be helped from the stage, unable to play or speak coherently. As Powell's incapacitation became apparent, Parker stood in one spot at a microphone, chanting "Bud Powell...Bud Powell..." as if beseeching Powell's return. Allegedly, Parker continued this incantation for several minutes after Powell's departure, to his own amusement and Mingus's exasperation. Mingus took another microphone and announced to the crowd, "Ladies and Gentleman, please don't associate me with any of this. This is not jazz. These are sick people." This was Parker's last public performance; about a week later he died after years of substance abuse.  Mingus often worked with a mid-sized ensemble (around 8-10 members) of rotating musicians known as the Jazz Workshop. Mingus broke new ground, constantly demanding that his musicians be able to explore and develop their perceptions on the spot. Those who joined the Workshop (or Sweatshops as they were colorfully dubbed by the musicians) included Pepper Adams, Jaki Byard, Booker Ervin, John Handy, Jimmy Knepper, Charles McPherson and Horace Parlan. Mingus shaped these musicians into a cohesive improvisational machine that in many ways anticipated free jazz. Some musicians dubbed the workshop a "university" for jazz.

Using a quote from the above article, answer the following question: What did he say about these Pepper Adams, Jaki Byard, Booker Ervin, John Handy, Jimmy Knepper, Charles McPherson and Horace Parlan?
Mingus shaped these musicians into a cohesive improvisational machine that in many ways anticipated free jazz.