New compositions (1984–present)
Andersson composes primarily for his band BAO, with vocalists Sjöholm and Körberg, but he keeps his older material alive by re-visiting it, as in Mamma Mia! and the Swedish version of Chess.
For a compilation album of the Glenmark duo Gemini, Andersson had Björn Ulvaeus write new Swedish lyrics for the re-recording of two songs from 1984 and 1987.
Andersson and Ulvaeus have continuously been writing new material; most recently the two wrote seven songs for Andersson's BAO 2011 album O klang och jubeltid, performed as usual by vocalists Sjöholm, Körberg and Kalle Moraeus. In July 2009, BAO, now named "The Benny Andersson Band", released their first international record, the album The Story of a Heart. It was a compilation of 14 tracks from Andersson's five Swedish-language releases between 1987 and 2007, including five songs now recorded with lyrics by Ulvaeus in English, and the new title song premiered on BBC2's Ken Bruce Show. A Swedish-language version of the title track, "Sommaren Du Fick" ("The Summer You Got"), was released as a single in Sweden prior to the English version, with vocals by Helen Sjöholm.
In the spring of 2009, Andersson also released a single recorded by the staff at his privately owned Stockholm hotel Hotel Rival, titled "2nd Best to None", accompanied by a video showing the staff at work. In 2008, Andersson and Ulvaeus wrote a song for Swedish singer Sissela Kyle, titled "Jag vill bli gammal" ("I Wanna Grow Old"), for her Stockholm stage show "Your Days Are Numbered", which was never recorded and released but did get a TV performance. Ulvaeus also contributed lyrics to ABBA's 1976 instrumental track "Arrival" for Sarah Brightman's cover version recorded for her 2008 album A Winter Symphony. New English lyrics have also been written for Andersson's 1999 song "Innan Gryningen" (then also named "Millennium Hymn"), with the new title "The Silence of the Dawn" for Barbara Dickson was performed live, but not yet recorded and released. In 2007, they wrote the new song "Han som har vunnit allt" ("He Who's Won It All") for actor and singer Anders Ekborg.
Ulvaeus wrote English lyrics for two older songs from Andersson's solo albums I Walk with You Mama ("Stockholm by Night", 1989) and After the Rain ("Efter regnet", 1987) for opera singer Anne Sofie Von Otter, for her Andersson tribute album I Let the Music Speak. Barbara Dickson recorded an Ulvaeus and Andersson song called "The Day The Wall Came Tumbling Down"; the song eventually was released by Australian Mamma Mia! musical star Anne Wood's album of ABBA covers, Divine Discontent. As of October 2012, Ulvaeus had mentioned writing new material with Andersson for a BAO Christmas release (also mentioned as a BAO box), and Andersson is busy writing music for a Swedish language obscure musical, Hjälp Sökes ("Help is Wanted") together with Kristina Lugn and Lars Rudolfsson, premiering 8 February 2013.
Andersson has also written music for a documentary film about Olof Palme, re-recording the track "Sorgmarch" from his last album as a theme throughout the film. The song "Saknadens rum and Kärlekens Tid", recorded 2004 by Helen Sjöholm with BAO, has also been performed in concert in English (lyrics by Ylva Eggehorn) by opera baritone Bryn Terfel. On 15 April 2013, it was officially announced by the EBU and the SVT that Andersson, along with Ulvaeus and the late Stockholm based DJ and record producer Avicii, had composed the anthem for the Eurovision Song Contest 2013. The song was performed for the first time in the Final on 18 May.
A new album of Andersson compositions presented in a choral style was released on 18 September 2015. "Kärlekens Tid" was produced in Andersson's Mono Music studio, under the direction of choirmaster Gustaf Sjökvist, who died before the album's release. Gustaf Sjökvists Choir, conducted by Cecilia Rydinger Alin, performed two concerts at Skeppsholmen on 20 September, featuring Benny Andersson on piano. The album includes songs in Swedish and English from a range of Andersson's projects, such as Chess, Kristina and BAO.
In November 2018, Deutsche Grammophon released Piano, a collection of ABBA tunes, tunes from Chess and original compositions, such as The Day Before You Came, all played by Andersson on solo piano.
Andersson reunited with ABBA in 2018. On 2 September 2021, via YouTube livestream, ABBA announced their upcoming virtual concert residency "ABBA Voyage", as well as the imminent release of an eponymous album, recorded between 2017 and 2021. The new record, their first studio album in 40 years, features ten tracks, including "I Still Have Faith In You" and "Don't Shut Me Down", which also were first shown in the aforementioned livestream event and released as two singles. On 5 November 2021, the Voyage album was released worldwide. On 27 May 2022, ABBA Voyage opened in a purpose-built venue named the ABBA Arena at the Queen Elizabeth Olympic Park in London.