Symphony X is a Progressive Metal band from New Jersey, USA. It was founded in 1994 by guitarist Michael Romeo. At the earlier stages of their career, the band signed a deal with the now extinct Zero Corporation Label, which was based in Japan – a country where Progressive Music is widely received. It was only after signing a contract with the European label Insideout that the band started to be popular outside Japan, mainly in mainland Europe.

Their official website, which started back in 1997 by a Brazilian fan, was a key factor to the diffusion of Symphony X work.

The music from Symphony X tends to be epic and powerful, with touches of opera choirs and classical music.