Allen started releasing solo recordings in 1971, but throughout his career achieved greater success through his songs being recorded by others. Allen scored his biggest success with the song "
I Honestly Love You", which he co-wrote with
Jeff Barry and which became a major hit in 1974 for
Olivia Newton-John. Her single reached number one in the United States and Canada and won two
Grammy Awards, for
Record of the Year and
Best Female Pop Vocal Performance for Newton-John. Allen also co-wrote "
Don't Cry Out Loud" with
Carole Bayer Sager, popularized by
Melissa Manchester in 1978, and "
I'd Rather Leave While I'm in Love", also co-written with Bayer Sager and popularized by
Rita Coolidge in 1979. One of his
signature songs, "
I Go to Rio", co-written with
Adrienne Anderson, was popularized in America by the group
Pablo Cruise. In 1976, Allen released an album,
Taught by Experts, which reached number one in Australia, along with the number one single "
I Go to Rio" and the Top 10 hit of a
Harry Warren standard "
The More I See You". The album also included the song "Quiet Please, There's A Lady On Stage" which was recorded by many artists including
Jack Jones and
Dusty Springfield. Although his recording career in the US never progressed, he performed in
Atlantic City and at
Carnegie Hall. He had three extended sold-out engagements at New York City's
Radio City Music Hall, where he became the first male dancer to dance with
The Rockettes and rode a camel during "I Go to Rio". Allen's most successful album was
Bi-Coastal (1980), produced by
David Foster and featuring the single "
Fly Away", which in 1981 became his only US chart single, reaching No. 55 on the
Billboard Hot 100. In addition, Allen co-wrote the
Patti LaBelle hit "I Don't Go Shopping", which reached the top 30 on the R&B chart in 1980. Allen co-wrote the song "
Arthur's Theme (Best That You Can Do)" with
Burt Bacharach,
Carole Bayer Sager and
Christopher Cross, for the 1981 film
Arthur. The song reached number one
in the US and the songwriters won an
Academy Award for Best Song. One lyric for the song, "If you get caught between the moon and New York City", was adapted from an earlier song that he and Bayer Sager co-wrote. Allen and Bayer Sager also co-wrote "You and Me (We Wanted It All)", which was recorded by
Frank Sinatra for his 1980 album
Trilogy. A video of Sinatra singing the song at Carnegie Hall was included as part of the
Sinatra: New York live performance
box set, released in late 2009. Allen performed on Australian television for many important occasions: in front of
Queen Elizabeth II in 1980 at the
Sydney Opera House, before
Prince Charles and
Princess Diana, once in
Melbourne and again in Sydney in 1981, at the opening of the
Sydney Entertainment Centre in 1983, where he unveiled for the first time his Australian "Flag" shirt, and the
1980 VFL Grand Final in Melbourne. His "Up in One Concert" of 1980 was a big ratings success across the country. When Australia won the
America's Cup in
1983, he flew to
Perth to sing before an audience of 100,000. In 1988, he opened for Frank Sinatra at
Sanctuary Cove, Queensland. In America, he appeared at the 30th anniversary of
Disneyland. He returned to recording on Arista with an album entitled
Not the Boy Next Door (1983). In 1990, he recorded his final album on RCA Victor,
Making Every Moment Count, which featured Melissa Manchester and
Harry Connick Jr. The song "Making Every Moment Count", a duet with Manchester, was co-written by
Seth Swirsky, who also produced a number of songs he co-wrote with Allen, including Allen's last-released single, "Tonight You Made My Day". One of his songs, '"
I Still Call Australia Home", became popular through its use in television commercials, initially for
National Panasonic and, since 1987, for
Qantas. Allen's most covered song is "
I Honestly Love You". On 23 September 2025, Barry Manilow released the Allen-penned (along with Dean Pitchford) song "Once Before I Go," a single from his forthcoming album "What a Time." The song originally appeared on Allen's 1983 Album "Not the Boy Next Door."
Broadway Allen made his
Broadway debut on 12 January 1971, in
Soon, a rock opera that opened at the
Ritz Theatre and ran for three performances. He starred in his own one-man revue on Broadway at the
Biltmore Theatre,
Up in One: More Than a Concert (1979), which ran for 46 performances. Allen recorded a live album called
Captured Live at Carnegie Hall, in which songs from his musical
Legs Diamond, were previewed.
Legs Diamond opened on Broadway at the
Mark Hellinger Theatre on 26 December 1988, with a book co-written by
Harvey Fierstein. The musical ran for 64 performances and 72 previews. After
Legs Diamond closed he returned to concert work, touring with
Bernadette Peters during the summer of 1989. Allen and Bernadette also performed in the 1983 Academy Award broadcast in an extended musical tribute to
Irving Berlin.
Other work • Allen appeared in a cameo role in the film ''
Sgt. Pepper's Lonely Hearts Club Band'' (1978). • Allen's live version of "Everything Old is New Again" can be heard on the soundtrack of the film
All That Jazz (1979). • Allen was the musical guest at
Miss Universe 1981. • Allen appeared in the 1982 television version of
The Pirates of Penzance (as the Pirate King). • Allen appeared as the "man in studio" in the TV series
Miami Vice's second-season premiere episode "
The Prodigal Son". • Allen did a pilot for a new
Name That Tune show in 1990, and the pilot for what became CBS's short-lived prime-time game show
The Hollywood Game (both projects were produced by
Marty Pasetta). He died the day of the series, which ended up being hosted by
Bob Goen due to Allen's illness, debuted. ==Personal life==