Question: Gerry Rafferty and Martin Johnson, have which mutual occupations?
Context: Snakes and Ladders is the fourth album by Gerry Rafferty.  It was released in 1980, following the success of his previous two albums, "City to City" and "Night Owl".  The album charted at No. 15 in the UK but only reached No. 61 in the US.  The album was released on CD in 1998 [EMI 7 46609-2] but deleted soon after that, and it got reissued on CD on August 2012 as a 2-CD set with "Sleepwalking."  Some of the songs are available on compilation albums.  One of the songs, "The Garden of England", was recorded at Beatles producer George Martin's AIR studio in Montserrat.  All the songs were original Rafferty compositions, though one – "Johnny's Song" – was a remake of a song which had been previously released by his former band Stealers Wheel, and another – "Didn't I" – was a remake of a song from Rafferty's 1971 album "Can I Have My Money Back". "I See Red" is a song written by Gerry Rafferty's brother, Jim Rafferty.  I See Red was first recorded by Anni-Frid Lyngstad of ABBA, under the name "Frida" for her first English-language studio album, "Something's Going On".  Lyngstad's version did not chart other than South Africa, although subsequent cover versions by other artists such as the Irish folk group, Clannad, included in their album, "Magical Ring", resulted in a moderate success.  Clannad's version was the follow-up single to their breakthrough hit "Theme from Harry's Game".  Gerry Rafferty himself also recorded a version on his 1992 album, "On a Wing and a Prayer". Gerald "Gerry" Rafferty (16 April 1947 – 4 January 2011) was a Scottish singer-songwriter best known for his solo hits "Baker Street", "Right Down the Line" and "Night Owl", as well as "Stuck in the Middle with You" recorded with the band Stealers Wheel. Can I Have My Money Back?  is the first solo album by Gerry Rafferty.  The distinctive cover design was by John Patrick Byrne and was the start of a long working relationship between Rafferty and the playwright.  The LP was well received, but performed poorly in charts and sales, in part because Rafferty had just left a well known band, The Humblebums.  The album also saw Joe Egan come on board, and the pair formed Stealers Wheel shortly afterwards. Martin Bennett Johnson (born September 9, 1985) is an American singer, songwriter and record producer.  In addition to being a songwriter and producer, he is the frontman of the pop rock band Boys Like Girls and the new wave band The Night Game. City to City is a 1978 album and the second studio album by Scottish singer-songwriter Gerry Rafferty.  It was Rafferty's first solo release in six years—and first release of any kind since 1975—due to his tenure in the band Stealers Wheel and subsequent legal proceedings which prevented Rafferty from releasing any new solo recordings for the next three years.  The album was strongly received, peaking at No. 1 in the US and going Platinum, as well as reaching No. 6 in the UK and achieving Gold status. " Baker Street", "Right Down the Line" and "Home and Dry" were successfully released as singles.  By October 2010, "Baker Street" had reached 5 million plays on British radio. North and South is the sixth studio album by Gerry Rafferty.  It was Rafferty's first studio album in six years and reunited him with producer Hugh Murphy.  The album got fair reviews from critics and fans.  The album was released as an LP and CD in 1988.  One of the singles was "Shipyard Town", also released on several compilation albums.  It was regarded by most of Rafferty's fans as the best album since "Night Owl".  After the rather, some felt, over-engineered nature of "Sleepwalking", the album was a welcome return to form with a more stripped-back nature and less fastidiously-engineered songs. Tommy Eyre (5 July 1949 – 23 May 2001) was a session keyboardist from Sheffield, England, who appeared on records by Joe Cocker, John Martyn, Alex Harvey, Greg Lake, Michael Schenker, Gary Moore, B.B. King, John Mayall, Gerry Rafferty, Tracy Chapman and Wham! .  He is perhaps most famous for playing on Joe Cocker's UK chart-topper "With A Little Help From My Friends", on which he arranged the distinctive organ introduction, and Gerry Rafferty's "Baker Street" and "Right Down the Line". "Night Owl" is a song by Gerry Rafferty.  It is the second track on his 1979 album of the same name.  It features a Lyricon solo played by "Baker Street" saxophonist Raphael Ravenscroft.  The song made the top five in the UK Singles Chart, and along with "Baker Street" is one of two solo efforts by Gerry Rafferty to accomplish this feat. Gerry Rafferty, released in 1974 on Transatlantic Records (TRA 270) (reissues included: Visa Records [Visa 7006]), is mainly a compilation of Humblebums material that Gerry Rafferty had written and performed while in that group.  It comprises most of the serious musical content of the last two albums released by that group, with the exception of "So Bad Thinking" (which came from the backside of his "Can I Have My Money Back?"  single).  The remaining content of those two albums were mostly humorous Billy Connolly compositions, although a few musical gems can be found among them, especially the ones in which Rafferty sings harmony.  The sound and feel of this album is similar to "Can I Have My Money Back? ", his first solo effort from 1971.  All song versions on this album (except "So Bad Thinking") are available in CD form on various Humblebums compilations.
Answer: singer, songwriter