At the time it was recorded, "Bohemian Rhapsody" was the most expensive single ever made. Recorded over many weeks and in a total of five different studios, Queen and producer Roy Baker managed to spend a great deal of money while still only laying down a total of 24 tracks—24-track recorders were the technology available at the time. Moving through five studios and re-formatting the tapes several times, the members of Queen, guided by Freddie Mercury's epic vision, labored heavily to make "Bohemian Rhapsody" a reality.
Queen was considered somewhat anarchic and wild on and off stage. Some then, would be surprised to learn that their work ethic in the studio was incredibly serious and disciplined: they often spent 14-hour days in the studio with Baker, day after day, during the making of A Night at the Opera. The process was not without conflict, but their agreement was that whoever had written the song got to guide the process, carefully showing others what he wanted. The whole band realized early on that "Bohemian Rhapsody" had the potential to become a big hit, and they threw themselves into it.
The process began with the ballad section, which seems simple enough: a three-part harmony over Freddie's solo singing and some ballad-y piano stuff. To give it the richness Freddie wanted, each part in the three-part harmony was recorded three times, then played back onto a single track. Then the three separate parts were played back together onto a single track—ending up with one vocal harmony track that actually has a total of nine recordings on it. This effect, called "bouncing" a track, can be created with the click of a button in Garage Band today, although some would argue that it's quite not the same. The old-school approach produced its own effects. In an article about the making of "Bo Rhap," Baker explained the process:
"We would do this to each background vocal part across the song and ended up with fourth generation dupes on just one of the parts. By the time we mixed two of the other parts together, the first part was up to eight generations. This was before we wore out the master and began making 24-track to 24-track tape transfers. Once that had happened, the distortion factor on those vocals was very, very high." (Source)
Then came the opera section, also laden with bounced tracks and rapidly changing vocals. Plus, when they went into the studio, Freddie and the rest couldn't resist making the opera part bigger and bigger:
"It was the first time that an opera section had been incorporated into a pop record, let alone a Number One. It was obviously very unusual and we originally planned to have just a couple of 'Galileos.' But things often have a habit of evolving differently once you're inside the studio, and it did get longer and bigger. The beginning section was pretty spot on and the end section was fairly similar, although we obviously embellished it with guitars and lots of overdubs. But the opera section ended up nothing like the original concept, because we kept changing it and adding things to it." (Source)
The approach to adding on more "Galileos" was serious analog, nothing like the cut-and-paste computer technology producers use today:
"The opera bit was getting longer, and so we kept splicing huge lengths of tape on to the reel. Every time Freddie came up with another 'Galileo', I would add another piece of tape to the reel, which was beginning to look like a zebra crossing whizzing by! This went on over a three or four day period, while we decided on the length of the section. That section alone took about three weeks to record, which in 1975 was the average time spent on a whole album." (Source)
Finally, they recorded the hard-rock section followed by a soaring return to quiet ballad. The rock section was more classic Queen, and production-wise, it resembles other songs and albums of theirs in more superficial ways. But the smoothness of the transition from opera section to rock conclusion should not be underestimated. Brian May's guitar-playing deserves some credit there, as does Freddie's versatile singing. All-in-all, "Bohemian Rhapsody" is a musical adventure worthy of being revisited, reviewed, and even imitated—although we doubt anyone could pull that off better than the Muppets.