Short answers, pulled from the story.
Bohemian Rhapsody was written entirely by Freddie Mercury, Queen's lead singer. Mercury described it as a "mock opera" that resulted from combining three songs he had been writing separately, and the song was all worked out in his mind before the band began recording.
Recording began on the 24th of August 1975 at Rockfield Studio 1 near Monmouth, South Wales. Four additional studios were used during production: Roundhouse, Sarm Studios, Scorpio Sound, and Wessex Sound Studios. The entire piece took three weeks to record.
Because the studios of 1975 only offered 24-track analogue tape, Mercury, Brian May, and Roger Taylor had to overdub themselves repeatedly and combine those recordings into successive sub-mixes. The opera section alone required 180 separate overdubs, and the tapes had to be bounced across eight generations.
Producer Roy Thomas Baker gave a copy to DJ Kenny Everett on the condition he not play it. Everett played it anyway, first teasing listeners with excerpts and then airing the full song fourteen times in two days. Audience demand was so intense that the unedited single was released and went to number one in the UK for nine weeks.
Mercury refused to explain the lyrics beyond saying the song was about relationships. Music scholar Sheila Whiteley suggested the lyrics reflect Mercury's personal turning point in 1975, when he had just begun his first love affair with a man after seven years with Mary Austin. Mercury himself reportedly told DJ Kenny Everett the lyrics were simply "random rhyming nonsense".
The promotional video, recorded in four hours on the 10th of November 1975 at a cost of £4,500, is credited with making promotional videos a standard practice for record companies. The Guardian stated it "ensured videos would henceforth be a mandatory tool in the marketing of music", and the video has been described as launching the MTV age.
Bohemian Rhapsody reached number one in the UK twice with the same version, making it the only single to achieve this. It held the top position for nine weeks in 1975 as the UK Christmas number one, and again for five weeks in 1991 following the death of Freddie Mercury.