The soundtrack to the film Deep Red (profondo rosso) was mainly composed and performed by the Italian progressive rock band Goblin. Director Dario Argento had originally contacted jazz pianist and composer Giorgio Gaslini to score the film, but he was unhappy with his output, deeming it "awful". After failing to get Pink Floyd to write music for the film, Argento turned back to Italy and found Goblin. In the final score, only three of Gaslini's original themes were retained however, in the film's original theatrical release, Gaslini was given full composer credit for the entire score, while Goblin were wrongly credited only as performers [i.e. "Music by Giorgio Gaslini, performed by Goblin"]. This was corrected in subsequent home video releases.
In 1996, the complete film soundtrack was re-released on CD by Cinevox, under the supervision of Claudio Simonetti. This release includes all the music featured in the film, as well as a remix of the main theme and two sound effects tracks from the film itself.
PS: track 25 ("deep shadows") is one of the most beautiful progressive tracks I ever heard!