In another 1959 CBC documentary, Columbia recording director Howard Scott is seen pleading with Gould before a take of Bach’s Italian Concerto for “a straight piano solo, without vocal obbligato.”

Schachtner fills in the instrumental colors — obbligato winds, vocal doublings, radiant strings — that might have swirled in Puccini’s mind.

It spotlights six-beat drumming, intertwined guitars, synthesizer and accordion obbligatos, call-and-response vocals, singing and rapping, cheerfully claiming a whole continuum of ideas.

“With Rita it was all one voice. Rita was like a pop singer, yet she could do these obbligato things, and it didn’t seem strange.”

The other was the whole first section of the fast movement, a solo in F major with obbligato flute, in which Florestan recalls happier days with Leonore at his side.