Kate Bush was "terrified" of losing her place mid-song every night during her 2014 London residency.
The reclusive Wuthering Heights singer returned to the stage after a 35-year absence for the 22-show Before the Dawn residency at the Hammersmith Apollo, and turned down multiple interview requests before and after the sell-out event.
She has now spoken about them for the first time with BBC 6 Music during an hour-long special radio show to promote the three-part live album she is releasing from the shows on 25 November (16).
During the interview, which airs in full on 20 November (16), she admits she was so nervous and because her mind tends to race ahead, leaving her scared she would forget her place in the song.
"I was terrified," she said. "The idea of putting the show together was something that I found really interesting and really exciting... but to actually step into it was something that I had to really work hard on because I was terrified of doing live work as a performer again.
"My head is always moving ahead just trying to get to the conclusion of whatever this journey is... But I was so terrified that if my mind wandered off that when I came back I wouldn't remember where I was. So I had to really fix myself, so that I would remember where I was in the song."
She added she changed her mind about doing live shows because she wanted a change from heading to the studio to work on albums. Kate also revealed she had to "really seriously build up to" making an official decision to perform again.
When asked if she would do more live shows, she replied, "It was an extraordinary thing to be involved in, especially to have got the response that we did. It was really magical. But I don't know. I don't know what I'm going to do next. I want to just do something new."