Anka said that he recorded two songs with Jackson in 1983, both intended for Anka's album 'Walk a Fine Line.' One of them, 'I Never Heard,' contains the identical vocal and piano line heard on 'This Is It,' Anka said. Anka said Monday that in the hours since he first heard the song he had reached a deal to receive half the publishing royalties. He called the situation an 'honest mistake.' The song takes its name from what would have been Jackson's comeback tour this summer. It now will serve as the title track to a concert film, which arrives for a limited run on Oct. 28, and an accompanying album that will be released in North America on Oct. 27. Anka said he heard from the special administrators to the Jackson estate around 2 p.m. 'They said, `Look, we get it. We made a huge mistake. ... We understand that this is your song.' I said I wasn't going to hold them up, and wanted what was right, and that's 50 percent. That was my vocal.' The version released late Sunday/early Monday features some new flourishes, namely backing vocals from Jackson's brothers that were added to the mix after Jackson's death June 25, sources familiar with the song's production confirm. They did not exist in any prior form of the song. Anka said he recently was listening to the vocals on the songs he recorded with the pop star and was thinking of ways to re-purpose them. 'I was going to take that track and do exactly what they did with somebody else. ... But I love what they've done and I do think it's an honest mistake.' 