I usually do not post sound files in the blog, if they are not uploaded by the artist, but this one I have to link to. So much for my ethics.
7 November 1971 Gary Burton played Jazztage in Berlin. According to Michael King´s "Wrong movements, A Robert Wyatt history", Burton did a solo concert with accompaniment for the opening and closing songs. Musicians were Robert Wyatt (dr), Terje Rypdal (g) and Neville Whitehead (b).
Run on over to YouTube, and listen to "Moonchild".
I can´t find this recording in the bootleg section at "Une Discographie de Robert Wyatt", so I guess no one has got this on CD or Vinyl?