Question: "Rain" is the second song released by "Australian Idol" series two runner-up Anthony Callea, it was released as a double A-side set features the song plus his recording of Simon & Garfunkel's song "Bridge over Troubled Water", Simon & Garfunkel were an American folk rock duo consisting of singer-songwriter Paul Simon, and which singer?
Context: Simon & Garfunkel were an American folk rock duo consisting of singer-songwriter Paul Simon and singer Art Garfunkel.  They were one of the best-selling music groups of the 1960s and became counterculture icons of the decade's social revolution, alongside artists such as the Beatles, the Beach Boys, and Bob Dylan.  Their biggest hits—including "The Sound of Silence" (1964), "Mrs. Robinson" (1968), "The Boxer" (1969), and "Bridge over Troubled Water" (1970)—reached number one on singles charts worldwide. Bridge over Troubled Water is the fifth and final studio album by American folk rock duo Simon & Garfunkel, released in January 1970 on Columbia Records.  Following the duo's soundtrack for "The Graduate", Art Garfunkel took an acting role in the film "Catch-22", while Paul Simon worked on the songs, writing all tracks except Felice and Boudleaux Bryant's "Bye Bye Love" (previously a hit for the Everly Brothers). American folk rock duo Simon & Garfunkel recorded songs for five studio albums.  Consisting of guitarist/singer-songwriter Paul Simon and singer Art Garfunkel, the duo first met as children in Kew Gardens Hills, Queens, New York in 1953, where they first learned to harmonize with one another and began writing original material. "Rain" is the second song released by "Australian Idol" series two runner-up Anthony Callea, and features on his self-titled debut album "Anthony Callea" (2005).  It was released as a double A-side set features the song plus his recording of Simon & Garfunkel's song "Bridge over Troubled Water", which he performed on "Australian Idol". "Bridge over Troubled Water" is a song by American music duo Simon & Garfunkel.  Produced by the duo and Roy Halee, the song was released as the follow-up single to "The Boxer" in January 1970.  The song is featured on their fifth studio album, "Bridge over Troubled Water" (1970).  Composed by singer-songwriter Paul Simon, the song is performed on piano and carries the influence of gospel music.  The original studio recording employs elements of Phil Spector's "Wall of Sound" technique using L.A. session musicians from the Wrecking Crew. "Hurts So Bad" is the third single released by "Australian Idol" series two runner-up Anthony Callea, and features on his self-titled debut album "Anthony Callea" (2005).  It was his third consecutive top ten single in Australia. "So Long, Frank Lloyd Wright" is a song written by Paul Simon that was originally released on Simon & Garfunkel's 1970 album "Bridge over Troubled Water".  It has since been released on several Simon & Garfunkel compilation albums.  It has also been recorded by the London Pops Orchestra and Joe Chindamo trio.  Art Garfunkel has stated that the origin of the song came from his request that Paul Simon write a song about the famous architect Frank Lloyd Wright while Simon has stated that he wrote the song, despite not knowing who Wright was.  Garfunkel sings lead on the majority of the song while Simon sings on the bridge. Recorded as Jerry Landis is a compilation album of music by singer, songwriter, and guitarist Paul Simon, released in 2006.  This album contains 18 songs recorded before Simon & Garfunkel released their first album, "Wednesday Morning, 3 A.M.".  All songs are by Paul Simon except the song "Beat Love", which is a contemporary recording by Art Garfunkel, recorded under the name "Artie Garr".  This album was released six years after an album of Simon & Garfunkel songs, from the same era, that contained a mix of Simon & Garfunkel recordings (under the name "Tom & Jerry"), and Paul Simon and Art Garfunkel songs.  He recorded many of the songs on these albums under different aliases, such as "Jerry Landis", "True Taylor" and "Paul Kane". "I Am a Rock" is a song written by Paul Simon.  It was first performed by Simon alone as the opening track on his album "The Paul Simon Songbook" which he originally recorded and released in August 1965, only in the United Kingdom.  Paul Simon and Art Garfunkel, as the American folk rock duo Simon and Garfunkel, re-recorded it on December 14, 1965, and included as the final track on their album "Sounds of Silence", which they released on January 17, 1966. Two Can Dream Alone is a compilation album by folk rock duo Simon & Garfunkel.  The album is a collection of songs from before they recorded their debut album "Wednesday Morning, 3 A.M.".  It also has solo recordings by both Paul Simon and Art Garfunkel during this era of their careers.  It contains all of Simon & Garfunkel's singles from these years.  Six years after its release, a similar album was released which contains all Paul Simon songs except for "Beat Love" by Art Garfunkel, which appears on both albums.  The songs on that album are also from their early years.
Answer: Art Garfunkel