The band's 15th LP Music From Another Dimension! will be released on November 6 after being pushed back a week.
Steve Tyler revealed that he met John Lennon's eldest son Julian in Los Angeles while working on American Idol, and said that he has sung on their album track 'Love Three Times a Day'.
"He's such a sweet f**king guy," Tyler told Rolling Stone. "And he's John's first son with that voice and sense of humour - gimme a break!"
Johnny Depp has also provided backing vocals to the track 'Freedom Fighter', but guitarist Joe Perry stated that the song may be kept for a future deluxe edition.
Talking about the album, Perry said: "Everyone wants to hear the same 'Dream On's and 'Walk This Way's, but that's not what I had in mind to be in a band - to be the best cover band you can be.
"We can be the best Aerosmith cover band out there, and I was getting tired of it. So I'm really glad to have this record."
Music From Another Dimension! is the band's first full album since 2004's Honkin' on Bobo.