Frank Anthony "Tony" Iommi is the well-known guitarist of Black Sabbath, and once cut off two of his fingers (not on purpose though). He was born on February 19, 1948 in Ashton, Birmingham England. He began playing music as a boy on the accordion but was soon influenced by the popular music of his day to begin saving up for his first guitar at the age of 14.
By the age of 18, he had booked his first gig in Germany and had set his sights upon embarking on a musical career path. He gave notice at his job at a machine shop, and as fate would have it, on his last day of work he caught his right hand in one of the machines and accidentally amputated the tips of his middle and ring fingers. The doctor treating him advised him that his guitar playing days were most likely over. A close friend soon renewed his hopes by presenting him with a recording by Django Reinhardt, a virtuoso jazz guitarist who had injured his hand as well. (Reinhardt only had 2 fingers on his fretting hand resulting from an injury by fire).
With his desire to play reborn, Tony designed a type of prosthetic device consisting of a thimble fitting over his missing fingertips with leather pads at the tip for better grip on the guitar's strings. While it's not a secret, Tony doesn't usually bring it up, and is rarely (if ever) photographed without his prosthetic, and his co-performers are often surprised to find out about his "handicap".
In addition to the prosthetic devices, Tony found that he could comfortably play on very thin gauge "light" guitar strings, yet was dissatisfied with these strings' thin, twangy sound. His solution to this problem was to detune the strings several steps down from their original tuning of EADGBE to a configuration of C#F#BEG#C#, a full step and a half down. This resulted in a deeper, darker tone being imparted to the notes played. Having only limited usage of his two injured fingers, Tony was mostly limited to utilizing chords of two or three notes, and found the "power chord" configuration of root-fifth-octave to be useful given his limitations.
In 1968, Tony formed a band called The Polka Tunk Blues band with local musicians Ozzy Osbourne, Geezer Butler and Bill Ward which later changed their name to Earth. The other members of this band also tuned their instruments down to match Tony, and played cover tunes and blues songs in their England neighborhood until finally changing their name to Black Sabbath, after a song they had recently written and titled after a Boris Karloff movie of the same name had become one of their most popular songs.
Black Sabbath's sound was marked for its distinctive darkness of tone quality (the detuned strings) usage of power chords and angular guitar riffs (Tony's missing fingers forcing him to think in different directions when soloing and playing melodic riffs) as well as their exploring of the darker sides of human nature and occult themes in their lyrics. It can be argued that the band might not have found this sound musically had not Tony been led to think and perform in new ways owing to the limitations imposed upon him by his amputations.
While Black Sabbath has endured numerous personnel changes over the years and faced waning popularity, there is no doubting that the music of Black Sabbath and the guitar style of Tony Iommi has influenced countless numbers of musicians and deeply affected the sound of popular music today, and has left an indelible stylistic imprint in heavy metal and hardcore and will doubtless for years to come.
Tony Iommi still records and tours as a solo artist as well as with Black Sabbath and also writes a regular column in Guitar World magazine.