Barcelona (Freddie Mercury and Montserrat Caballé song) contained "Exercises in Free Love" from "The Freddie Mercury Album". The 1992 version of the 7" Spanish record had another version of "Barcelona" on the B-side, and the rare 1987 12" Hong Kong record was one-sided and had a unique sleeve. Most 5" CDs contained two or three versions of "Barcelona" and "Exercises in Free Love". Most 7" record and 5" CD covers featured Mercury and Caballé singing on a stage with an orchestra on the background, though the Portuguese version pictured them in a static studio photo. The 1992 reissue 7" records contained another version of the singing artists,
Barcelona (Freddie Mercury and Montserrat Caballé song) rather than forced tenor, which was common in his other recordings. The song has been described as a rare textbook example of a combination of pop and opera singing which accentuated their differences. Whereas Mercury articulates his every word, Caballé focuses on the tone; her lines are much harder to comprehend, and further, she uses both English and Spanish languages. Consequently, she keeps her part melodic throughout all the song at the expense of the text, whereas Mercury has to resort from singing to nearly shouting at the crescendo part in order to deliver his words. Mercury was reportedly amazed