Short answers, pulled from the story.
Paul McCartney said the song came from a dream about his mother, Mary Patricia McCartney, who died of cancer in 1956 when he was fourteen. She appeared in the dream telling him: "It will be all right, just let it be." Mal Evans, the Beatles' road manager, also claimed the song originated from a vision McCartney had of Evans during the group's meditation sessions in India in March 1968.
The original single, released on the 6th of March 1970, was produced by George Martin, who mixed the orchestration quietly. Phil Spector produced the album version, released on the 26th of March 1970, with more prominent orchestration and a different guitar solo. A 2003 release, Let It Be... Naked, restored Ringo Starr's original drumming and stripped away Spector's additions.
"Let It Be" debuted on the Billboard Hot 100 at number 6 in 1970. It was the highest chart debut the Hot 100 had recorded at the time. The song climbed to number one in April 1970 and held that position for two weeks, and also reached number one in Australia, France, Italy, and New Zealand.
McCartney's microphone failed for the first two minutes of his performance at Live Aid on the 13th of July 1985, leaving the performance inaudible to the stadium audience. David Bowie, Bob Geldof, Alison Moyet, and Pete Townshend returned to the stage to back him up. McCartney re-recorded his vocals afterward for home video releases.
Aretha Franklin released the first version of "Let It Be" in January 1970. McCartney had sent a demo to producer Jerry Wexler in late 1969, who passed it to Franklin. Her recording reached stores before the Beatles' own single, which was issued on the 6th of March 1970.
Rolling Stone ranked "Let It Be" at number 8 among the greatest Beatles songs and at number 20 on its 500 Greatest Songs of All Time. The Grammy organization inducted the song into its Hall of Fame in 2004. In The 100 Best Beatles Songs by Stephen J. Spignesi and Michael Lewis, it ranked third overall and topped the book's separate fan poll.