"It was one of my joys to work with John and Villa-Lobos during the writing of the Concerto. The composer sat at the huge semi-circular desk with a pot of black thick coffee, several cigars and ashtrays all around working on several compositions at once, while watching a TV at intervals. All the time wearing a hat..." Apparently Sebastian wasn't comfortable with Villa's first version of the Cadenza, so together they put together this:
Sebastian recorded this work on a Heliodor LP with Stuttgart Radio Symphony Orchestra, with Hans Schwieger. I'm not sure if this has ever been transferred to CD. Here is a YouTube video of the LP:
This piece has been very lucky with recordings. The top modern exponent is Robert Bonfiglio; his recording on RCA with the New York Chamber Symphony under Gerard Schwarz is my favourite.