Queen

        Although Mercury's speaking voice naturally fell in the baritone range, he delivered most songs in the tenor range. Biographer David Bret described his voice as "escalating within a few bars from a deep, throaty rock-growl to tender, vibrant tenor, then on to a high-pitched, perfect coloratura, pure and crystalline in the upper reaches". Spanish soprano Montserrat Caballé, with whom Mercury recorded an album, expressed her opinion that "the difference between Freddie and almost all the other rock stars was that he was selling the voice". As Queen's career progressed, he would increasingly alter the highest notes of their songs when live, often harmonising with seconds, thirds or fifths instead. Mercury suffered from vocal fold nodules and claimed never to have had any formal vocal training.