Dr. John’s Friday afternoon interview at the New Orleans and Jazz Heritage Festival’s Allison Miner Music Heritage Stage drew one of the largest audiences in the stage’s history.

“It’s in the pantheon of big crowds,” Music Heritage Stage producer Ben Sandmel said.

Bruce Raeburn, curator of Tulane University’s Hogan Jazz Archive, proved an astute and appreciative interviewer.

Raeburn’s questions centered on Dr. John’s 2014 Louis Armstrong tribute album, “Ske-Dat-De-Dat: The Spirit of Satch.” It’s a stylistically diverse project loaded with, as Dr. John put it, a gang-and-a-half of guest talent.

“All of the guys in the band was kicking,” Dr. John said. “And that goes with your eardrums.”

As for the origin of his Armstrong tribute album, Dr. John said: “Louis came to me in this dream and he said, ‘Do my music your way.’ Hey, if you get an order from above, you better know that’s right.”

Dr. John previously devoted albums to the music of Ellington and Johnny Mercer. Saving New Orleans’ own Armstrong until now, Raeburn said, was a strategic maneuver by Dr. John. Also another example of him exposing new generations to great music from the past.

A question from Raeburn about when Dr. John first heard Armstrong’s music took the singer-pianist back to his childhood. His father operated a record shop that sold traditional and bebop jazz, rhythm-and-blues, blues and hillbilly records. Musicians would listen to it all, Dr. John said. “Everybody would pick up on everything.”

The 45-minute interview session also featured a few solo performances by Dr. John at the electric piano. He performed a terrific rendition of Armstrong’s “Dippermouth Blues.”

Members of the audience stepped to a microphone during a Q&A session that followed Raeburn’s interview. A British festivalgoer asked Dr. John how he manages to make the English language sound so sexy.

“Hey,” Dr. John replied, “whatever you do, you gotta be sexy.”

Another British-accented questioner asked about the late Cosimo Matassa, who died in September. Dr. John got his early recording experience at Matassa’s New Orleans studios, the source of dozens of national hits in the 1950s and ’60s.

“Cosmo was a big influence on me and all the people he came around,” Dr. John said. “I remember him being the humblest, sweetest cat you ever met.”

When another questioner asked Dr. John if he’d experienced a life-changing moment, the musician, not saying a word, simply played some boogie-woogie piano.

Raeburn took the discussion back to Armstrong before closing. He asked Dr. John how to keep Armstrong’s spirit and love alive.

“If we can take Louis’ spirit,” Dr. John said, “and take it with us all the way to the ends of time, we can do something for somebody that’s special. There ain’t no way around it. We gotta do something special.”