Question: When was the Austrian band formed that made the album Solo?

Context paragraphs:
Seiler und Speer: Seiler und Speer is an Austrian band from Bad Vöslau that formed in 2014.  The band is composed of comedian and actor Christopher Seiler and film producer Bernhard Speer.

Opus (Austrian band): Opus is a pop-rock group from Graz, Austria.  Formed in 1973, the group remains active today.  The band is chiefly known for its 1985 single release, "Live Is Life", which reached the Top 10 in several European countries.

I Am Yours (song): "I Am Yours" is a song performed by Austrian band The Makemakes.  The song represented Austria in the Eurovision Song Contest 2015 where it finished second to last place, scoring zero points.  It was released as a digital download in Austria on 6 March 2015 as the lead single from their debut studio album "The Makemakes (album)" (2015).  The song was written by Jimmy Harry, Dominic Muhrer, Paul Estrela, Florian Meindl and Markus Christ.  The song has peaked at number 2 on the Austrian Singles Chart.

Danna International (Offer Nissim Presents): Danna International (Offer Nissim Presents) is the first album by Israeli singer Dana International, released in 1993.  In her early days it was common to see her first name spelt "Danna".  The album's catalogue number is IMP Dance 1993 - IMP 2004, although quite a few copies of the album misprint the catalogue number as "IMP 4004" on the CD label.  The album has covers of Baccara's popular 1970s disco hit "Yes Sir, I Can Boogie" and the Queen song "The Show Must Go On" sung in Hebrew, with the chorus in English.  The song "Fata Morgana" appears on this album in two different versions.  Singer Ofra Haza and the Austrian band Erste Allgemeine Verunsicherung recorded totally different songs each with the same name.  The "Danna International" album includes songs sung in three languages; Hebrew, Arabic and English.

Das was wir sind: "Das was wir sind" is the debut single from the album "Diese Stadt," by the Austrian band Mondscheiner.  It was released on 7 July 2006 and reached #10 on the Austrian charts.

Erste Allgemeine Verunsicherung: The "EAV" (Erste Allgemeine Verunsicherung, German for "First General Confusion/Uncertainty/'Uninsurance'") is an Austrian band that was formed in 1977.

Solo (Opus album): Solo is the fifth album by Austrian pop rock band Opus.  It was released in 1985.  It peaked at #8 on the Ö3 Austria Top 40 Longplay.  The first single "Rock on the Rocks", peaked at #21 on the Ö3-Hitparade.  The second single, "Idolater", peaked at #24 on the Ö3-Hitparade.

Opus Dei (album): Opus Dei is the third studio album by Laibach, released in 1987.  It features "Geburt einer Nation" ("birth of a nation"), a German cover of Queen's "One Vision", and two reworkings of the Austrian band Opus' sole hit single "Live Is Life".  The Opus song became the German language "Leben heißt Leben" and the English language "Opus Dei".  "The Great Seal" is the national anthem of the NSK State, the lyrics taken from Churchill's speech We shall fight on the beaches.  A new arrangement of the song appears on Laibach's album "Volk", with the title "NSK".  On "Volk", the song is credited to Laibach and Slavko Avsenik, Jr.

Count Basic: Count Basic are an Austrian band who play a variety of R&B, trip hop, acid jazz and smooth jazz.  The band's principal members were guitarist Peter Legat and the two vocalists Kelli Sae and Valerie Etienne but the band decided to go on only with Kelli Sae after the first album.

Golden Dawn (band): Golden Dawn is an Austrian band formed by Stefan Traunmüller, originally as a one-man black metal project, in 1992.  It eventually attracted the attention of two influential Austrian metallists, Ray Wells of Pazuzu and Martin Schirenc of Pungent Stench and Hollenthon, which led to a compilation appearance and eventually a recording contract with Dark Matter Records.

Supporting paragraphs: Solo (Opus album) Opus (Austrian band)
Answer: in 1973