Elton John Has Meltdown While Recording 'Who Believes in Angels?' Album

Elton John burst into a fit of rage while recording his upcoming album "Who Believes in Angels?" ... and he even posted behind-the-scenes footage of his outburst for all to see.

Check it out ... the Rocket Man exploded after producer Andrew Watt stood up for himself ... telling the musical legend he has no patience. The next scene shows Elton mouthing off and slamming his headphones onto his keyboard.

His collaborator Brandi Carlile even admits she has no clue why Elton wanted to make a record with her ... adding that she had "a hard time connecting" with him. She also accuses EJ of being "prone to bouts of insecurity especially where the stakes are high." Yikes.

Elton even seemingly quits the project at another point in the video ... dramatically ripping up a piece of paper and announcing he's "done."

He defends his sour attitude in a voiceover, explaining ... "The reality is, I was exhausted. I had a lot of doubt. I was a nightmare. I was angry, I was tired, I was irritable."

The "Cold Heart" hitmaker eventually overcomes his volatile mix of self-consciousness and anger to complete the album, recorded in 2023 ... which he announced Wednesday is due to debut on April 4.

Elton describes "Who Believes in Angels?" as "one of the most difficult creative processes" he's ever been through ... adding that he chose to work with Brandi because he knew they could make something special.