Freddie’s Voice
Freddie’s voice is considered one of the greatest vocalists in popular music history, having a very distinct voice. Although his speaking voice was in the baritone range, his singing voice was that of a tenor. His recorded vocal range spanned nearly 4 octaves (falsetto included), with his lowest recorded note being the F below the bass clef.His highest note ever recorded was the D that lies nearly 4 octaves above.
Source: dailymail.co.uk
Mercury also delivered technically difficult songs in a quite a powerful way. However, due to his vocal nodules (which he declined surgery for), he would often lower the highest notes in their concerts. Apparently, Freddie never even had any formal vocal training.