Now and Then (lost overdub session of Beatles song; 1995)
Now & Then (also known as "Miss You" and "I Don’t Want to Lose You") is the title of an unreleased song written by John Lennon. The song originally recorded as a demo in 1977 with further overdubs by the surviving members (Paul McCartney, George Harrison and Ringo Starr) of The Beatles as a possible third single to The Beatles Anthology project. However, The Beatles' work on the song ceased and The Beatles version remained unreleased.
John Lennon's original demo
"Now And Then" was recorded by Lennon during his "retirement" period when he was no longer a recording artist under contract and looking after his son, Sean Lennon, full time. During this time (between 1975-1980), Lennon would record a numerous rough demo recordings by himself (either on guitar or piano) with nothing more than a cassette boombox. Since these were never meant to be heard by the public, audio quality wasn't a concern. The piano demo cassette recording for "Now And Then" was recorded in 1977. Lennon would come out of retirement in 1980 and many of the songs during this down period were recorded professionally on the sessions for the album; Double Fantasy . On December 8th, 1980 John Lennon would be murdered. The remainder of the songs recorded would be included on the posthumously released Milk and Honey album in 1984. The song "Now And Then" was not included in the Double Fantasy sessions and would not make it past the demo stage in Lennon's lifetime.
The Beatles version
The Beatles' company Apple Corps, had been working on an official documentary on the band's career since 1968. With the band's legal issues and the death of member John Lennon delaying the project it wouldn't be until 1989 when the surviving members and Yoko Ono made plans to produce what would become the "Anthology" series.  During the project's production, it was decided that The Beatles would record new material for the series.
In January 1994, Paul McCartney approached Yoko Ono, Lennon's widow, believing she would have some of his unused recordings. Ono gave McCartney three cassette tapes from Lennon's retirement period, one of which was found in Lennon's New York apartment with the words For Paul written in Lennon's handwriting. The cassettes contained rough demo recordings of the songs; "Free As A Bird", "Real Love", "Grow Old With Me" (which was previously released in demo form on Milk and Honey) and "Now and Then," featuring Lennon on piano and vocals. 
The three remaining Beatles soon began work on all demos with Jeff Lynne producing. Work on the demos began 11th February 1994 with "Free As A Bird", followed by work on "Now And Then" on 22nd June, 1994. Work continued on "Now And Then" during the "Real Love" sessions in early February and May 1995. Producer Jeff Lynne had worked on the mono cassette demos to bring them up to a quality were they could be worked on.  However, "Now And Then" proved more of a technical challenge, as a 60-cycle mains hum could be heard through-out the whole recording. From reports, the sessions for "Now And Then" were difficult and ending with a frustrated Harrison declaring the song "fucking rubbish". Work stopped on the recording in May 1995.
Anthology singles and non-appearance of the third single
"Free As A Bird" was released as a single on 4th December, 1995. It was meant with mixed reviews and missed the number 1 chart spot in the UK to Michael Jackson's "Earth Song" (to which, Jackson's record company Sony sent EMI a turkey stuffed with "Free As A Bird" singles).
The next reunion single, "Real Love" was released 4th March, 1996. Although critically it fared better, the chart performance was still disappointing (reaching #4 in the UK and #11 in the US). Part of the reason behind the songs performance in the UK was due to it being rejected from the BBC's Radio 1 playlist.
When it came time for the third single to be released on Anthology 3 in October 1996, the opening reunion song was replaced with an unreleased orchestral opening to the White Album track "Don't Pass Me By" titled "A Beginning". Reports in the media highlighted the technical issues Lynne and The Beatles had with recording the song, but didn't rule out a future release. 
Post Anthology Availability
To date, no content from the overdub sessions in 1994 and 1995 have resurfaced either officially or unofficially. The original demo of the track has since surfaced on the bootlegs and YouTube. In 2009, a version of the cassette without the hum was circulated on the John Lennon bootleg CD At Home 
In a 2009 interview, McCartney shared his interest in completing the song with Lynne and Starr, using the archived tracks that Harrison provided before his death. The only other thing needed is approval from Harrison's estate (owned by his widow, Olivia Harrison) and from Yoko Ono, the status of their stances are unknown. In 2012 McCartney talked about the song about and Harrison's rejection during the sessions the documentary about Lynne's career Mr Blue Sky: The Story of Jeff Lynne & ELO.
In a 2021 interview with The New Yorker, McCartney again mentioned his wish to finish the song as a possible "future project". 
Fan made recreations
Since the availability of the cleaner cassette, there have been several fan edits of the song circulating on bootlegs.
- John Lennon - Complete Home Demo Recordings 1975-1980 Vol 1 (5CD With Slipcase) Misterclaudel. MCCD-497-501
- The Story Of The Beatles' Anthology Project - Sound On Sound
- Now And Then (song) - The Paul McCartney Project (the-paulmccartney-project.com)
- "The Beatles Anthology" sessions (Feb 11, 1994 - 1996) - The Paul McCartney Project (the-paulmccartney-project.com)
- The Story Of The Beatles' Anthology Project (soundonsound.com)
- The Story of... 'Earth Song' by Michael Jackson - Smooth (smoothradio.com)
- John Lennon – At Home (2009, CD) - Discogs
- Paul McCartney Doesn’t Really Want to Stop the Show | The New Yorker